2013年度 化学専攻 特別講義3 有機典型元素化学特論@立教大学 第3回 8/7 1 担当:中央大学理工学部応用化学科 山下 誠 最先端有機元素化学:最新論文からのトピックス 論文を読む際の注意点 ・論文の背景においてどのような研究がなされてきたか? 要点を整理してまとめる。 ・この論文において得られた結果は何か? 論文に書かれている全ての反応式・全てのグラフの縦軸と横軸の定義・全ての略号の意味に加えて Supporting Informationも含めて化合物データ・各種スペクトルの解釈・分子構造情報の詳細・ 化合物の物性などを理解する ・この論文において何がこれまでの報告と違うのか? ・それはどのような工夫によって得られたものか? ・得られた結果を説明するための実験は他に考えられるか? ・自分ならこの論文に何を足してさらに次のアプローチを考えるか? (可能なら)そのアプローチに対して必要な他の事実を他の論文から探して 実現可能性に関して論ぜよ 大学院の講義の目的は 「知識を広げると共に、それを応用した研究戦略を身につける」 です。 上記赤字の部分を自ら考えなければ、 高い授業料を払って時間を無駄にするだけ。 自分の頭を使って考えることに喜びを覚えない人は 今すぐに化学をやめる方が良いです。 最先端有機元素化学①:最新論文からのトピックス 2 Phosphorus as a Lewis Acid: CO2 Sequestration with Amidophosphoranes Lindsay J. Hounjet, Christopher B. Caputo, Douglas W. Stephan* Angew. Chem. Int. Ed. 2012, 51, 4714. CO2snapper: Compounds containing both acidic and basic P,N functionalities have been prepared. Of these, two amidophosphoranes containing highly reactive PN bonds within four-membered rings react rapidly with CO2, resulting in relief of ring strain. These compounds demonstrate the utility of phosphorus as a Lewis acid for small-molecule Prof. Stephan University of Toronto タイトルとTOCグラフィックから読み取れること ・リン原子がルイス酸になる MOF: metal organic framework ・五配位のリン化合物(phosphorane)の話 Introductionから読み取れること ・二酸化炭素の話、特に貯留の話:例としてMOF, FLP FLP: frustrated Lewis pair 北川進 (京都大学) Omar Yaghi (UCLA) Reviews: Org. Biomol. Chem. 2008, 6, 1535 Dalton Trans. 2009, 3129 ACIE 2010, 49, 46. Dow studies of globalby reactivity, from the of 3(CO) “frustrated Sasaki andderived co-workers, whoconcept used [Ru introduction of CO2 into a solution of 1 in toluene at 100 8C mix12]/KI Lewis actor in [12] ious and pairs”, that is, systems in which steric congestion precludes produced the unique formatoborate complex [TMPH]n of H2 ave been zeolites, neutralization. These [*] Dr. A. E. Ashley, Prof. D. systems O’Hare offer latent Lewis acidity and [HCO2B(C6F5)3] (2) in quantitative yield; the reaction can in group 3 basicity forResearch reaction with small molecules. In this vein, we[13] be monitored conveniently by solution 19F NMR spectroscowell as Chemistry Laboratory, University of Oxford mperature ] [14] and othersRoad,have exploited 17),for and the Mansfield Oxford OX1 3TAthis (UK)notion for the heterolytic py.[10] The 1H NMR (C7D8) spectrum of 2 revealed a downe occuractivation of dihydrogen and subsequent application of the field shift of the signals for the NH hydrogen atoms of about An alterFax: (+ 44) 1865-272-690 2 mpounds E-mail: [email protected] resulting systems in metal-free catalytic hydrogenation and Reaction of FLP with H /CO of carbon -workers Reaction of FLP with H 2 2 2 to [email protected] to olefins.[15, 16] Herein, we demonstrate that the strategies Ge2 and Dr. A. L. Thompson Angewandte tal-based concept of frustrated Lewis pairs can be exploited to effect ree sysChemie Chemical Crystallography, for their the reversible binding Inorganic of carbonChemistry dioxideLaboratory under mild conum-based ons. AlSouth Parks Road, Oxford OX1 3QR (UK) ditions. nation of hydride 2 [**] We A thank the EPSRC for 6support, Oxford for covered a Junior solution of B(C F5)3 andBalliol PtBuCollege, orn and 1 3 in C6H 5Br was hydride” Research (A.E.A.), and Dr. Nick Rees (CRL, Oxford) with an Fellowship atmosphere of carbon dioxide, resulting in for the tegies to ounds to NMR support. immediate precipitation of aScience white 2006, solid 314, (1), which xide is its 1124. was Supporting information for this article is available on the WWW Scheme 2. Reversible reduction of CO2 to formate 2 with H2 activated isolated in 87 % yield (Scheme 1). This product exhibited reactivity. niversity of under http://dx.doi.org/10.1002/anie.200905466. by a frustrated Lewis acid–base pair 1. eact with ed. E-mail: Reaction of FLP ed transi-Fig. 1. Syntheses of compounds 1 to 4. with CO2 ! 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 9839 vert it toAngew. Chem. Int. Ed. 2009, 48, 9839 –9843 NOVEMBER the other 2006 VOL 314 SCIENCE www.sciencemag.org p systems into P!N, e reports GC analysis was pe CH3, H) must occur (Scheme 4). This hypothesis was corrobenes.[9, 10] diameter: 0.53 mm, borated by the detection of H2O·B(C6F5)3 hydrogen-bonded (hold, 2.5 min), th were also with various anions in the electrospray mass spectrum.[19] Introduction: Frustrated Lewis Pair (FLP) Communications microanalyses were politan University. Received: Septemb Published online: N . Grimme, HAN . Scheme 1. Reversible CO2 uptake and release by frustrated phosphine– ACIE 2009, 48, 6643. borane Lewis pairs. 31 1 11 1 resonances in the P{ H} and B{ H} NMR spectra at d = 46.1 and !2.7 ppm, respectively. The 19F NMR spectrum showed signals at d = !133.5, !160.4, and !166.0 ppm, typical of C6F5 substituents on a four-coordinate boron center. The 13C NMR spectrum of 1 showed resonances expected for the constituent phosphorus and boron fragments as well as a signal at d = Keywords: amine methanol Scheme 3. Proposed mechanism for the disproportionation of 2 into 4 and CO2. ACIE 2009, 48, 9839. Scheme Thermolysis [TMPH][HOB(C )3] (3)oxygen and [TMPH]6F5acyl 160 8C. 4.The attack ofofB(C F ) on the atom of 2 6 5 3 [MeOB(C6F5)3] (4), and production of CH3OH. produces an intermediate A (Scheme 3), which is thought to give rise to the broad doublet observed at d = 174.5 ppm in [1] a) http://www.c Ruedy, M. Sato S. Menon, T. N Tausnev, Scien [2] a) K. B. Lee, M Chem. Res. 2 DOI: 10.1002/anie.201103600 arren E. Piers,* and Masood Parvez CO 2 Reduction , 2500 UniVersity DriVe NW, Calgary, Alberta, Canada T2N 1N4 Introduction modified FLP Stoichiometric Reduction of CO2 to2:CO by Aluminum-Based Reaction of FLP with H /CO Reaction of CO with P/AlCl -FLP of 2 Frustrated Lewis Pairs** and NH ・BH (hydride equivalent) afluo- 7, 2010; E-mail: [email protected] Scheme 1 2 2 orm a ethyld the was mhe thedramatic rise in the consumption of fossil fuels since the C(O)ndustrial revolution has resulted in rapid increases in quiv) tmospheric CO2 levels, exacerbating global climate pidly [1] hange. While mitigating emissions through reduced conerate pidly umption and improved efficiency will most likely offer the with est solutions, technologies such as carbon capture and CO2 torage t3SiH continue to be developed in the hopes of eliminating is a industrial emissions.[2] In addition to the environmental ome ative 2 3 4 3 3 Gabriel M!nard and Douglas W. Stephan* motivation, the rising costs and dwindling supplies of fossil uels have prompted efforts to develop alternative energy ources. While this has generated a number of clever nnovations in energy technology,[3–8] one approach that has ic C1 such arnered attention and addresses both the environmental and JACS 2010, 132, 10660. urrent lternative energy issues is based on the concept of utilizing es its The ammonium hydridoborate ion pair 1 formed by treatment of CO fuels. Indeed, one perturbation of this10 ficient 2 as a Cthe 1 source FLP B(Cfor 6F5)3/2,2,6,6-tetramethylpiperidine (TMP) and hydrogen minant mM, C6D5Br)economy” reacted with CO the presence dea is the(32“methanol espoused byin Olah someof 2 (2-4 atm) of [9, 10](18 equiv) at 56 °C to afford the previously reported7 Et3SiH 0er years ago. To avoid further environmental issues and mple, formatoborate 2 exclusively (see Scheme 1).11 The reaction was eal thermodynamic this vision requires versus the ductswith monitored by 1H and 19realities, F NMR spectroscopy, and integration [11, 12] uctive eduction an ofinternal CO2 standard by photochemically generated H3SiH (C6H5CF3, 9 mM) revealed that no Et 2. was 7 ucing consumed. Thus, the formation of 2 is reversible,splitting there does While intense efforts arealthough targeting the photocatalytic The species Mes3P(C(OAlI3)2 (1) was readily synthesized JACS 2010, 132, 1796.analogues in a similar fashion to chloride and bromide [Eq. (1)].[16] The compound is isolated by precipitation after Reaction of CO2 with P/AlI3-FLP to CO ACIE 2011, 50, 8396. 5 minutes following the combination of the reagents. The Al NMR resonance for 1 is observed at 20 ppm and is 27 spectively. However, in most cases the desired prod- gest that the phosphonium salt uct was obtained in good to excellent yields but low bipyramidal configuration upon diastereoselectivity. Higher reaction temperatures and Lewis base DMF. One of the lower catalyst loading (2.5 mol%) had only a marginal oxygen atoms and the carbo influence on the yield. The authors proposed that the occupy the 5apical positions, reaction proceeds via the activation of the Lewis formed hypervalent bond. Cyanohydrin trimethylsilyl e basic imines by the coordination to the Lewis acidic termediates, e.g., for the synthe diphosphonium salt. Recently Terada et al. reported about another fun- and b-amino alcohols.[39] The damental carbon-carbon bond forming reaction that acetal as an aldehyde equivalen can be catalyzed by phosphonium salts. They investi- dehyde dimethyl acetal, catalyz gated the Diels–Alder reaction of a,b-unsaturated ported by Mukaiyama et al.[30] amides and cyclopentadiene catalyzed by various the synthesis of cyanohydrin phosphonium salts (Scheme 10).[26] The addition of from aldehydes and TMSCN ca Tf2O increased the yield significantly. It was con- and easily accessible pho firmed by control experiments that Tf2O alone did (Scheme 12).[40] Aliphatic, arom not catalyze the reaction at all. In the presence of cat- aldehydes were converted unde alyst 11, Z-configurated dienophiles gave the corre- yielding the corresponding cyan ACIE 2010, 49, 5788. 2011, ethers 133, 18463. sponding Diels–Alder product in excellentJACS yields and in good to excellent y Thomas Wernerthe e REVIEW high endo-selectivity (> 97%). In contrast, E-configu- a,b-unsaturated aldehydes rated amide dienophiles showed lower yields and a the desired product was obser REVIEW preference to form the exo-products. salt The ability of the employed phosphonium salts to [a] as a Lewis acid catalyst in this reaction function Table 1. Mukaiyama-aldol reaction. strongly depended on the structure and the substituents at the phosphorus atom. A five-membered dioxaphosphacycle was thereby crucial for catalytic activity. The performed coordination studies using 11 and DMF as a model system revealed that DMF coordi- Introduction 3: FLP other than Group 13/15 Group 14 Lewis Base Phosphonium Salt Organocatalysis Lewis酸としてのphosphonium Scheme 2. Hypervalent interaction between a phosphonium salt and a Lewis base. Tetrahedron 2006, 62, 401. Aldehyde Nucleophile Cat. Scheme 10. Diels–Alder reaction catalyzed by 11. the apical position of the trigonal bipyramidal ar8 rangement.[26,28] Yield [%] 98[b] This review covers the application of phosphonium salts as Lewis acidic catalysts under homogeneous conditions as well as the use of chiral derivatives as asymmetric (phase-transfer) catalysts. decreased with increasing steric demand of the sub- nates to the Lewis acidic organophosphorus com76 repound (Scheme 11). The performed NMR studies sugstituent R2 at the nitrogen and R6 at7 the silicon, spectively. However, in most cases the desired prod- gest that the phosphonium salt arranged in a trigonal bipyramidal configuration upon coordination of the uct was obtained in good to excellent7 yields but 67 low diastereoselectivity. Higher reaction temperatures and Lewis base DMF. One of the two catechol moiety lower catalyst loading (2.5 mol%) had only a marginal oxygen atoms and the carbonyl oxygen of DMF 11. Formation and coordination mode of the DMF/ Scheme 12. Cyanosilylation of alde 2 C!C Bond Forming Reactions occupy the apical positions, thus stabilizing the influence on the yield. TheScheme authors proposed that 7 54 the phosphonium salt 11 complex. and selected examples. reaction proceeds via the activation of the Lewis formed hypervalent bond. In the course of their investigations to explore novel basic imines by the coordination to the Lewis acidic Cyanohydrin trimethylsilyl ethers are versatile in1474 asc.wiley-vch.de ! 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim metal-free Lewis acidic catalysts Mukaiyama et al. in- diphosphonium salt. termediates, e.g., for the synthesis of a-hydroxy acidsAdv. Sy 7 53 vestigated the use of phosphonium salts as catalysts in Recently Terada et al. reported about another fun- and b-amino alcohols.[39] The cyanosilylation of an several carbon-carbon bond forming reactions.[29,30] damental carbon-carbon bond forming reaction that acetal as an aldehyde equivalent, namely E-cinnamalJACS 2008, 130,salts 10890. They successfully employed diphosphonium 7 can be catalyzed by phosphonium salts. They investi- dehyde dimethyl acetal, catalyzed by 7 was first reand 8 as a catalyst in Mukaiyama-aldol reactions of gated the Diels–Alder reaction of a,b-unsaturated ported by Mukaiyama et al.[30] Plumet et al. reported 7 71[c] aldehydes with silyl enol ethers and ketene silyl ace- amides and cyclopentadiene catalyzed by various the synthesis of cyanohydrin trimethylsilyl ethers tals (Table 1). In all cases, the reactions proceeded phosphonium salts (Scheme 10).[26] The addition of from aldehydes and TMSCN catalyzed by the simple この論文を読む上での → wis Acid: CO2 Sequestration with s** This Work 1: Synthesis of Amidophosphorane of ring-strained amidophosphorane opher B.Synthesis Caputo, and Douglas W. Stephan* and its reaction with CO2 6 no reaction δH 4.68 (br q, 1JHH = 5 Hz) 13CO /CD Cl 2 2 2 gas has prompted widee. To date, a number of sequester this gasNHusing XeF2 PPh2 zeolites, activated carbon, δ 94.4 (d, J = 980 Hz) MOFs).[1] While some of δ −45.6 increasing scale, efforts to (t, J = 625 Hz) rategies for CO2 capture 1) Nの脱プロトン δ 2.28 (dd, J = 4.4 Hz, δ 3.15 (s) J = 2.4 Hz) 2) Pへ求核攻撃 of metal-free, frustrated (n-BuLi, NEt3 ecent attention.[2] In 2009, ではダメだった) ing of CO2 by borane/ δ 153.1 (d, J = 8 Hz) nt work by the groups of ν = 1696 cm selves,[6] has demonstrated 黄色 参考:5配位三方両錐構造 ap d FLPs for the conversion δ −57.0 eq ap: apical (d, J = 664 Hz) eq E CO. eq: equatorial δ −44.6 eq Scheme 1. Synthesis (d, J = 679 of Hz)2–4. ap d/base combinations conP chemistry, less attention variety of FLP systems m the original systems has methyl signal at d = 2.67 ppm. With the amine functionality P P 4 H 1 3 PH H FH CO P [7] 1 PF PF C P 1 PF ! 1 PF 1 PC −1 the 31P{1H} spectrum shows a doublet at d = !57.0 ppm, with JPF = 664 Hz. The corresponding 19F NMR signal is seen at d = !34.2 ppm. IR data for 4 show a characteristic carbonyl absorption band at 1696 cm!1. Collectively, these data suggest that 4 is the carbamatofluorophosphorane Ph2PF(oC6H4N(Me)CO2), and this formulation was confirmed by Xray crystallography (Figure 2).[12] Insertion of CO2 into the Angewandte ring with activated P!N bond of 3 results in a six-membered Chemie 1 This Work 2: Crystal Structure of 3 and 4 Crystal Structure of 3 Scheme 2. Synthesis of 6–8. 7 phorane PhPF2(o-C6H4NHMe)2 (5), an ion abstraction by Me3SiO3SCF3 gener C6H4NMeH)2][O3SCF3] (6). The spect compounds closely matched those derivatives. Crystallographic data of 6 lation and revealed P···N separations estingly, both amine H atoms are suggesting hydrogen bonding, althoug of about 2.4 ! indicate that this i Consistent with the reactivity describ of 2 equiv of tBuLi to 5 resulted in the PhP(o-C6H4NMe)2 (7), which was isola 75 % yield. The 31P{1H} NMR spectru nucleus with a singlet at d = !58.7 p spectrum demonstrates the C2 mole a single NMe resonance at d = 2.55 p Treatment of 7 with 1 atm of CO2 und an elongated P!O bond (1.775(1) ! and 1.778(1) !) in each of two molecules in the asymmetric unit. Within 4, the geometry about P is trigonal bipyramidal with the carbamato O occupying an axial position trans to F. The C!O and C=O bonds in the CO2 fragment of 4 average 1.330(2) and 1.212(2) !, respectively, which are slightly longer than those seen in tBu3PCO2B(C6F5)3 (1.299(2) !, 1.208(2) !) and (Me3C6H2)2PCH2CH2B(C6F5)2(CO2) (1.284(4) !, 1.209(4) !). Compounds 3 and 4 are both rare examples of crystallographically characterized phosphoranes, and to the best of our knowledge, 4 is also the first known pentacoordinate phosphorane containing a carbamato substituent. Figure 1. POV-ray depiction of 3. Although kinetically Figure hindered insertion CO2 into the 2. POV-ray depictionof of 4. P!N bond of (CF3)3PMe(NMe2) has been previously reported two crystallographically independent molecules to proceed over several Angew. Chem. Ed. 2012, –4717 ! 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim daysInt. to give51, a4714six-coordinate = zwitterionic carbamatophosphate,[13] the facile insertion of crystallographically independent molecules. The N atom occupies an axial position opposite F, although the N!P!F CO2 into the P!N bond of 3, relieves strain within the fourangles (164.4(3)8 and 165.1(3)8) are somewhat distorted from membered ring, thereby dramatically accelerating the reac結合3本による角度の和が360° tion. It is noteworthy that 4 is thermally robust, as itFis linearity, presumably in response to constraints imposed by unchanged on heating to 120 8C in toluene for 1 h. the equatorially disposed anilido Cipso. The geometry of the = amido unit is nearly planar, as the sum of the angles about N is Related compounds incorporating a second o-N-methylsum of angles around N = 356° C 3568 and the N!Cortho distances of 1.439(9) ! and 1.442(10) ! aniline group were prepared (Scheme 2). Oxidative fluorinaPh P 1.439(9) Å C−N結合は tion of PhP(o-C6H4NHMe)2 with XeF2 produced the phosare typical of single bonds. The C!C bonds within the anilido Me 通常の長さ 1.442(10) Å in ring are similar to those within neighboring Ph rings, Ph contrast to1.842(7) the dearomatization observed within metal comÅ N O 1.775(1) Å plexes of the amidophosphine ligand.[14] 1.839(6) Å N The exposure of a bright-yellow THF solution of 3 to 1.778(1) Å Phtemperature results in its immediate C 1 atm of CO2 at ambient Me C–O av. 1.330(2) Å discoloration, and NMR analysis P performed C shortly thereafter indicates complete conversion to a new species (4). The O C=O av. 1.212(2) Å 1 H NMR spectrum Ph of 4 shows a singlet N-methyl resonance at 164.4(3)° d = 3.15 ppm, and the loss of its coupling to both P and F is ! 165.1(3)° consistent with rupture of the P N bond within 3 to F accommodate CO2. The 13C{1H} NMR spectrum shows the B(C6F5)2 X線で得られる結合距離・角度は CO2 unit as a doublet at d = 153.1 ppm with 2JPC = 8 Hz, while O B(C6F5)3 the 31P{1H} spectrum shows a doublet at d = !57.0 ppm, with 末尾の桁の後ろに括弧書きで O tBu P C 1 JPF = 664 Hz. The corresponding 19F NMR signal is seen at C–O av. 1.299(2) Å Mes P C C–O av. 1.284(4) Å 3 標準偏差が記されている 3 C=O av. 1.209(4) Å d = !34.2 ppm. IR data for 4 show a characteristic carbonyl O C=O av. 1.208(2) Å O !1 absorption band at 1696 cm . Collectively, these data suggest Scheme 2. Synthesis of 6–8. that 4 is the carbamatofluorophosphorane Ph2PF(oC6H4N(Me)CO2), and this formulation was confirmed by X- unchanged on heating to 120 8C in toluene for 1 h. nilido Cipso. The geometry of the as the sum of the angles about N is Related compounds incorporating a second o-N-methylaniline group were prepared (Scheme 2). Oxidative fluorinaces of 1.439(9) ! and 1.442(10) ! 8 tion of PhP(o-C6H4NHMe)2 with XeF2 produced the phos- 2 The C!C bonds within the anilido within neighboring Ph rings, in . Angewandte Communications tion observed within metal comne ligand.[14] instantly produced PhP(o-C H N(Me)CO ) (8), which was isolated in 80 % yield. The P{ H} NMR spectrum of 8 NH ht-yellow THF solution ofN 3 XeF to 2 showed a single peak at d = !68.6 ppm, and the loss of J , which was made evident by the singlet NCH signal in the mperature results in itsPPh immediate 2 H H NMR spectrum, was consistent with CO insertion into nalysis performed shortly thereeach of the chemically equivalent P!N bonds. The H and C{ H} NMR data were also consistent with the formulation nversion to a new species (4). The of 8 as the double insertion product. Use of CO revealed ws a singlet N-methyl resonance at a strong signal at d = 152.8 ppm in the C{ H} NMR spectrum and IR spectroscopy of 8 showed the expected carbonyl of its coupling to both P and F is absorption at 1697 cm . The formulation of 8 was also confirmed by its X-ray f the P!N bond within 3 to structure (Figure 3), which showed the pseudo-C -symmet1 C{ H} NMR spectrum shows theδ −58.7 (s) ric geometry of the dicarbamatophosphorane, wherein P 2 153.1 ppm with JPC = 8 Hz, while a doublet at d = !57.0 ppm, with nding 19F NMR signal is seen at 4 show a characteristic carbonyl !1 δH 2.55 (d, 3JPH = 6.8 Hz) . Collectively, these data suggest δP −68.6 (s) Scheme 2. Synthesis of 6–8. atofluorophosphorane Ph2PF(oδC 152.8 (d, 1JPC = 8 Hz) ormulation was confirmed by XνCO = 1697 cm−1 [12] 2). Insertion of CO2 into the sults in a six-membered ring with phorane PhPF2(o-C6H4NHMe)2 (5), and subsequent fluoride ion abstraction by Me3SiO3SCF3 generated the salt [PhPF(oC6H4NMeH)2][O3SCF3] (6). The spectral parameters of these compounds closely matched those of their monoaniline Figure1.7635(8), 3. POV-ray depiction of 8. PーO: 1.7773(8) Å derivatives. Crystallographic data of 6 confirmed the formuOーPーO: 174.27(4)° lation and revealed P···N separations of 3.05–3.12 !. Inter直線に近いアピカル結合 oxygen donors occupy both axial positions, while the C estingly, both amine H atoms are oriented atoms of F, the aryl groups lie in the equatorial plane. The = towards lengths of mutually trans P!O bonds were found to be suggesting hydrogen bonding, although the H···F separations 1.7635(8) and 1.7773(8) !, with an O!P!O angle of [15] 174.27(4)8. The C!O and C=O bonds in 8 average 1.339(1) of about 2.4 ! indicate that this interaction is weak. This Work 3: Double Insertion of CO 6 4 31 2 2 1 3 3 1 13 PH a possib 3 (Schem tion in 2 1 1 13 13 1 2 !1 [12] Scheme 3 2 amido d reminisc develop insertion reported HC(NR molecul In su four-me equivale substrat These fi capabili PV Lewi efforts w Received Published . Keyword Lewis ac ipso [1] a) A O. M Row Scie instantly produced PhP(o-C6H4N(Me)CO2)2 (8), which was isolated in 80 % yield. The 31P{1H} NMR spectrum of 8 uto, and Douglas W. Stephan* showed a single peak at d = !68.6 ppm, and the loss of 3JPH, Stephan* which was made evident by the singlet NCH3 signal in the 1 H NMR spectrum, was consistent with CO2 insertion into d wideeach of the chemically equivalent P!N bonds. The 1H and 13 mber of C{1H} NMR data were also consistent with the formulation as using of 8 as the double insertion product. Use of 13CO2 revealed a strong signal at d = 152.8 ppm in the 13C{1H} NMR spectrum carbon, and IR spectroscopy of 8 showed the expected carbonyl ome of absorption at 1697 cm!1. fforts to The formulation of 8 was also confirmed by its X-ray capture structure (Figure 3),[12] which showed the pseudo-C2-symmetustrated ric geometry of the dicarbamatophosphorane, wherein In 2009, borane/ oups of nstrated nversion a possibility, it is also noteworthy that the resonance forms of 3 (Scheme 3) suggest the possibility of an FLP-type description in which a charge-separated P!N bond consists of an Consideration about FLP Reactivity CO2 Scheme 3. Resonance forms of 3. It can be considered that 3 is in resonance with ring-opening and charge-separated form amido donor and a phosphonium acceptor. This view of 3 is reminiscent of a B/P FLP, (C6H2Me3)2PCH2CH2B(C6F5)2, developed by Erker and co-workers.[16] In this regard, the CO2 4 insertion chemistry discussedshowed herein is FLP also analogous amidophosphorane property to that reported for the four-membered rings of boron imidinates, Cf. HC(NR)2B(C6F5)2, which are also thought to react with small molecules via an open FLP form.[17] Scheme 1. Synthesis of 2–4. In summary, amidophosphoranes 3 and 7, containing the ns consis of 2–4. four-membered rings, react rapidly to capture of one and two ttention 132, 13559. equivalents of CO2, respectively.JACS These2010, compounds bind the systems substrate in a manner analogous to related FLP systems. ems has methyl signal at d = 2.67 ppm. With the amine functionality These findings have prompted further study of the acceptor at d = 2.67 ppm. With the amine functionality ! of electron-poor phosphonium cations to provide unaffected by fluorination, facile F abstraction from capabilities at work, 1 by fluorination, facile F! abstraction from 1 by V P Lewis acid centers for FLP chemistry. The results of these d Lewis Me3SiO3SCF3 yields [Ph2PF(o-C6H4NHMe)][O3SCF3] (2), yields [Ph2PF(o-C H NHMe)][O SCF ] (2), 6 4 3 3 efforts will be reported in due course. What can we do next?...... as been a rare example of a compound containing both acidic le of a compound containing both acidic phosphonium and pendant amine functionalities. Received: The February 20, 2012 Group 4 and pendant functionalities. The 31 1 amine Published variety P{ H} NMR spectrum of 2 reveals a strongly deshielded P online: April 4, 2012 spectrum of 2 reveals a strongly deshielded P 1 hes, we nucleus with a doublet resonance at d = 94.4 ( JPF = 980 Hz), doublet resonance d1 = 94.4 (1JPFof = 980 Hz), Figure 3.atPOV-ray depiction amidophosphoranes · carbon dioxide · ons and while the H spectrum8. is largely unchanged, exceptKeywords: for Lewis acids and bases · phosphonium · pnictogens spectrum is largely unchanged, except for hosphoa downfield shift of the NH signal to d = 5.20. ift of the NH signal to d = 5.20. The combination of unquenched Lewis acidic and basic s in FLP oxygen donors occupy both axial positions, while the Cipso nation of unquenched Lewis acidic and basic pnictogens within 2 prompted our investigation of its nophosatoms of the aryl groups lie in thin 2 prompted our investigation of the itsequatorial plane. The . 9 現代化学における情報戦①:ChemDrawを使いこなせ ChemDrawショートカット 例:酸素を書く Oをタイプ Oをタイプ Oをタイプ 自動的に水素原子を補完 http://pute.seesaa.net/article/152301606.html http://pute.seesaa.net/article/152727364.html http://d.hatena.ne.jp/gyrase/20120303 化学ポータルサイトChem-Station紹介記事 http://www.chem-station.com/blog/2012/12/post-466.html 10 最先端有機元素化学②:最新論文からのトピックス 11 Coplanar Oligo(p-phenylenedisilenylene)s Based on the Octaethyl-Substituted s-Hydrindacenyl Groups Fukazawa, A.; Li, Y.; Yamaguchi, S.; Tsuji, H.; Tamao, K. J. Am. Chem. Soc. 2007, 129, 14164. The silicon analogues of the oligo(p-phenylenevinylene)s (Si-OPVs) with highly planar structures have been synthesized using a newly developed ligand, the 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl (Eind) group. Their X-ray crystal structures and spectroscopic data demonstrate that the π-conjugation effectively extends over the Si-OPV framework. Notably, tetrasiladistyrylbenzene exhibits an orange fluorescence even at room temperature both in solution and in the solid state, which is attributable to the effective extension of conjugation. To the best of our knowledge, the tetrasiladistyrylbenzene is the first emissive Si=Si derivative even at room temperature. タイトルとTOCグラフィックから読み取れること ・OPV[oligo-(p-phenylenevinylene)]のケイ素誘導体の話 Si=Si二重結合がベンゼンを挟んでいる ・Eind基という配位子が新しく合成された 玉尾皓平 勇人 深澤愛子 京都大学名誉教授 東京大学准教授 名古屋大学准教授 ・この化合物は溶液状態・固体状態でオレンジの蛍光を発する Introductionから読み取れること ・Si=C,P=P,Si=Siなどの重い二重結合は ・P=C, P=P, Si=Si, Ge=C, Ge=Geのオリゴマーやポリマーが合成されたが Oligomer and Polymer of Heavy Double Bond P=C polymer JACS 2006, 128, 8836. ACIE 2002, 41, 2389. P=P polymer Inorg. Chem. 2003, 42, 5468. JACS 2004, 126, 2268. 12 Oligomers of Group 14 Double Bonds Conjugated Si=Si bonds Conjugated Ge=C, Ge-Ge bond Organometallics 2000, 19, 2835. ACIE 1997, 36, 2503. Organometallics 2004, 23, 3088. ACIE 2000, 39, 3703. ACIE 2007, 46, 5783. 13 This Work 1: Synthesis of Dibromosilane 3 Synthesis of Eind-Br Synthesis of 3 14 This Work 2: Synthesis of Disilene and Bis(disilene) Synthesis of bis(dibromosilane) 4 Synthesis of disilene 1 and bis(disilene) 2 Stable solid! 15 This Work 3: Crystal Structure of 2 Crystal Structure of 2 真ん中のベンゼン環の中心にC2対称軸が存在 = SiーSi 2.156(2) Å SiーC 1.860(6); 1.876(6); 1.911(5); 1.902(5) Å Si周りの結合角の和=両方360° 16 This Work 4: Photophysical Properties of 2 1 vs 2: 5 vs 2: 7 vs 2, 6 vs 1: Tip Si Tip Si Tip 5 Eind Eind Si Ph Eind Si Ph Ph Si Si Si Eind Ph Si Eind 1 Eind 2 H Tip H H Si Tip C Ph C Ph C C Si Ph C Ph C H Tip H H 6 7 Figure S4. Electronic spectra of Si-OPVs 1 and 2 in n-hexane at ambient temperature. 参考:蛍光発光のメカニズム UV-vis absorption of 1 (gray) and 2 (black solid line) (Jablonski図) luminescence spectrum of 2 (black dotted line, excited at 460 nm) excitation spectrum of 2 (black broken line, observed at 620 nm) luminescence spectrum: excitation spectrum: 17 This Work 5: Luminescence and MOs 18 Figure S5. Photographs of compound 2. (a) solid in sealed tube in the dark (b) solid under irradiation at 254 nm (c) solution in hexane under irradiation at 254 nm 計算レベルはB3LYP/6-31G(d) What can we do next?...... 現代化学における情報戦②:webを最大限活用せよ 参考文献の探し方 19 Elsevier 1. 元の論文のURLがわかっている場合 その論文の引用文献にリンクが張ってある場合が多い ACS Wiley RSC 各参考文献へのリンクが羅列されているところで Ctrlキーやappleキーを押しながらリンクをクリックしていくと、タブが連続して開く 2. 元の論文のURLがわからない場合 参考:山下研website: http://www.chem.chuo-u.ac.jp/~element/ 2-1. Article LocatorやOrganic Chemistry reference resolverを使う このあたりに参考文献書式をコピー&ペーストして searchボタンをクリック(J. Am. Chem. Soc. 1996, 118, 7004.) それぞれオリジナルのwebsiteをbookmarkしても良い http://alocator.web.fc2.com/ http://chemsearch.kovsky.net/ 化学ポータルサイトChem-Stationにも紹介記事あり http://www.chem-station.com/blog/2011/02/-chemistry-reference-resolver.html http://www.chem-station.com/blog/2011/02/post-243.html http://www.chem-station.com/blog/2011/02/-firefox.html 2-2. DOI (digital object identifier)を使う 現在発行されている全ての論文にはdoiという 固有の文字列が与えられている (書式: 雑誌を表す数字/論文番号, 例: 10.1021/ja9100276) http://www.doi.org/ へアクセスし、論文に記載されているdoiを入力 自動的に該当する論文のウェブページへ移動できる なお、ページ番号が決定する前後でdoiは不変(=ASAP時点で登録も可能) 最先端有機元素化学③:最新論文からのトピックス 20 Iodomesitylene-Catalyzed Oxidative Cleavage of Carbon−Carbon Double and Triple Bonds Using m-Chloroperbenzoic Acid as a Terminal Oxidant Miyamoto, K.; Sei, Y.; Yamaguchi, K.; Ochiai, M. J. Am. Chem. Soc. 2009, 131, 1382-1383. Transition metal-catalyzed oxidative cleavage of carbon−carbon multiple bonds has emerged as a powerful tool in organic synthesis. High-valent oxometals, mostly of Ru, Os, Mn, Mo, W, and Re, were used catalytically as reactive oxygen transfer agents to the multiple bonds. Reported here for the first time are the organocatalytic versions of the oxidative cleavage reactions. Our method involves use of iodomesitylene as an effective organocatalyst, which generates an active aryl(hydroxy)-λ3-iodane 5 in situ, and m-chloroperbenzoic acid (m-CPBA) as a terminal oxidant under metal-free conditions. Cyclic and acyclic olefins as well as aliphatic and aromatic alkynes were smoothly cleaved to carboxylic acids under the organocatalytic conditions. タイトルとTOCグラフィックから読み取れること ・アルケンやアルキンのC-C結合を切断してカルボン酸にできる ・触媒はヨードメシチレンで酸化剤がmCPBA TOCから読み取れること ・遷移金属、特に高原子価金属オキソ錯体での ・酸化的切断の ・ はmCPBAにより 落合正仁 徳島大学教授 Oxidative Cleavage of C-C Multiple Bonds JACS 2002, 124, 3824. ACIE 2004, 43, 3303. Science 1998, 281, 1646. 21 Iodobenzene-Catalyzed Oxidation Reaction 4: p-iodotoluene JACS 2005, 127, 12244. ACIE 2005, 44, 6193. Synlett 2006, 798. Org. Lett. 2005, 7, 2933. Chem. Commun. 2006, 2483. 65% yield 25% ee Synlett 2007, 538. Chem. Commun. 2007, 1224. 22 This Work 1: Optimization of Condition Directly related stoichiometric oxidation using hypervalent iodine reagent Assumption: Can PhI be oxidized in situ? JACS 2007, 129, 2772. possible mechanism for oxidative cleavage Tableより、 ・ = = ・ ・ ・ 添加剤等について ・ ・ ・ best 23 This Work 2: Substrate Scope of Oxidation ・ ・ ・ ・ 24 This Work 3: Proposed Catalytic Cycle Proposed catalytic cycle Kinetics to show the pre-equilibrium Detection of intermediate by CSI-MS special case of Michaelis-Menten What can we do next?...... 25 現代化学における情報戦③:参考文献デジタルライブラリ 参考文献を紙で整理するのはもう古い? ReadCube Evernote Mendeley Papers 新着論文チェックはRSSで! 26 化学ポータルサイトChem-Station紹介記事 http://www.chem-station.com/blog/2011/11/-readcube.html http://www.chem-station.com/blog/2010/04/post-155.html http://www.chem-station.com/blog/2009/03/-evernotepdf.html EndNote 紙でプリントアウトする利点もまだまだある ・パソコンやタブレットが無くても読める ・一部切り抜いて実験ノートに貼り付け可能 ・ペンで書き込みすることが可能 化学ポータルサイトChem-Station紹介記事 http://www.chem-station.com/yukitopics/topic_lifehack_1.htm http://www.chem-station.com/blog/2009/11/rss.html http://www.chem-station.com/blog/2009/01/-angewandte-chemierss.html Chem-Stationより 「ものすごくかいつまんで言うなら、RSSとは「ニュースやブログなどの"最新見出しだけ"を記述したコード」のことです。 別の見方をすれば「更新状況に応じて最新の状態に保たれる、リアルタイム性のあるブックマーク」でもあります。」 RSSリーダーと呼ばれるソフトやウェブサイトを活用すると、自分が気になるブログやウェブサイトの更新状況がチェックできる →ジャーナルの新着論文チェックに最適!いろいろなものが出回っているので「RSSリーダー」で検索すべし 他にも「有機化学美術館」など、普段からチェックすべきウェブサイトを 自分で見つけて化学を最大限楽しむべし! Chem-Station代表 山口潤一郎 准教授 (名古屋大学伊丹研究室) 専門は新規合成反応開発を 基盤とした天然物合成など 最先端有機元素化学④:最新論文からのトピックス 27 Ona Illa, Muhammad Arshad, Abel Ros, Eoghan M. McGarrigle and Varinder K. Aggarwal “Practical and Highly Selective Sulfur Ylide Mediated Asymmetric Epoxidations and Aziridinations Using an Inexpensive, Readily Available Chiral Sulfide. Applications to the Synthesis of Quinine and Quinidine” タイトルとTOCグラフィックから読み取れること J. Am. Chem. Soc. 2010, 132, 1828. ・ ・ ・ TOCから読み取れること ・ ・ Heating one of the most abundant naturally occurring inorganic chemicals (elemental sulfur) with one of the most readily available homochiral molecules (limonene) gives a one-step synthesis of a chiral sulfide which exhibits outstanding selectivities in sulfur ylide mediated asymmetric epoxidations and aziridinations. In particular reactions of benzyl and allylic sulfonium salts with both aromatic and aliphatic aldehydes gave epoxides with perfect enantioselectivities and the highest diastereoselectivities reported to date. In addition reactions with imines gave aziridines again with the highest enantioselectivities and diastereoselectivities reported to date. The reactions are scaleable, and the sulfide can be reisolated in high yield. The epoxidation has been used as the key step in a convergent and stereoselective synthesis of each of the diastereoisomers of the cinchona alkaloids, quinine and quinidine. V. K. Aggarwal University of Bristol Limitation of Current Epoxidation By Sulfur Ylide 28 1,2-ジアリールエポキシドしか合成できない: 1,2-アリールアルキル体、α,β-不飽和体などは良い基質に Org. Biomol. Chem. 2008, 6, 4502. キラルなスルフィドの合成法が多段階に及ぶことが多い JACS 1996, 118, 7004. J. Org. Chem. 2005, 70, 4166. Eur. J. Org. Chem. 2000, 1077. Synlett 1999, 1328. Tetrahedron Asymmetry 1991, 2, 367. Chem. Commun. 2009, 5763. Tetrahedron Lett. 2001, 42, 57. J. Org. Chem. 2001, 66, 5620. Tetrahedron Lett. 2002, 43, 5427. Chem. Asian J. 2008, 3, 1657. JACS 2003, 125, 10926. Adv. Synth. Catal. 2008, 350, 2483. 29 This Work 1 キラルスルフィドのワンポット大量合成 Original report: JACS 1959, 81, 3430. ベンジルスルホニウムイリドの反応 This Work 2 アリルスルホニウムイリドの反応 ベンジルスルホニウムイリドの反応によるアジリジン合成選択性の起源 30 This Work 3 合成戦略 → Teoc: Wikipediaにキニーネの全合成に関する面白い話が・・・ 31 レポート課題について s-またはp-ブロック元素の化合物に関する過去5年以内の論文を読み、 以下の点に関してA4用紙数枚程度にWORDファイルでまとめてPDFとし、 WORDおよびPDFの両方を8/15までに山下へemailで提出(学籍番号と名前を明記のこと) [email protected] (email提出後には一日以内に山下より返信します。無ければ届いていないので成績がつきません。) 各項目は後ろに行けば行くほど重要 ・論文の背景においてどのような研究がなされてきたか? 要点を整理してまとめる。TOCの絵の貼り付け+論文内容の一言説明でもOK ・この論文において得られた結果は何か? ・この論文において何がこれまでの報告と違うのか? ・それはどのような工夫によって得られたものか? ・得られた結果を説明するための実験は他に考えられるか? ・自分ならこの論文に何を足してさらに次のアプローチを考えるか? またそのアプローチに対して必要な他の事実を他の論文から探して 実現可能性に関して論ぜよ ただし他の人と論文が重なってはいけない。 読むべき論文を決定した時点で山下へメールして重複の有無を確認すること。(学籍番号と名前を明記) 早く確認すればするほど論文を読む時間は増えるし、重複の可能性も少ない。 ラボの同級生・先輩・後輩・教員とのディスカッションはもちろんOKですが 最終的に自分の力で書ききることが最も自分の身になります。 成績評価は出欠代わりの小テストに加えて レポート内容の論理性・妥当性を判定して絶対評価でつけます (=全員Sも全員Dもありうる) 32
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