Synthesis and structural characterization of gold-(I), -(III) and silver(I) complexes of the ylide ligand Ph3PCHC(O)NMe2. Crystal structure of [(AuPPh3)2{µ-C(PPh3)C(O)NMe2}]ClO4
摘要:
The reaction between [AuCl(tht)] (tht = tetrahydrothiophene) and the ylide Ph3P = CHC(O)NMe2 gives [AuCl{CH(PPh3)C(O)NMe2}] 1, which reacts with chlorine to give [AuCl3{CH(PPh3)C(O)-NMe2}] 2 and with the same ylide and NaClO4 to form [Au{CH(PPh3)C(O)NMe2}2]ClO4 3. The analogous silver complex [Ag{CH(PPh3)C(O)NMe2}2]ClO4 4 is obtained by the reaction of AgClO4 with the ylide in molar ratio 1:2. The phosphonium salt [Ph3PCH2C(O)NMe2]ClO4 reacts with [Au(acac)(PPh3)] (acac = acetylacetonate) to give [Au{CH(PPh3)C(O)NMe2}(PPh3)]ClO4 5 or [(AuPPh3)2{mu-C(PPh3)C(O)NMe2}]ClO4 6 depending on the reaction conditions. The structure of 6 was confirmed by an X-ray diffraction study at -95-degrees-C [space group P1BAR, a = 11.572(3), b = 11.836(3), c = 21.627(7) angstrom, alpha = 78.29(2), beta = 87.19(2), gamma = 75.65(2)-degrees, R = 0.076]; the Au...Au bond length is 2.938(1) angstrom.
Copper(I)-Catalyzed Asymmetric 1,4-Conjugate Hydrophosphination of α,β-Unsaturated Amides
作者:Yan-Bo Li、Hu Tian、Liang Yin
DOI:10.1021/jacs.0c09654
日期:2020.11.25
hydrophosphination of α,β-unsaturated amides is accomplished by virtue of the strong nucleophilicity of copper(I)-PPh2 species, which provides an array of chiral phosphines bearing an amide moiety in high to excellent yields with excellent enantioselectivity. Furthermore, the dynamic kinetic resolution of unsymmetrical diarylphosphines (HPAr1Ar2) is successfully carried out through the copper(I)-catalyzed conjugate
Borrowing Hydrogen: Indirect “Wittig” Olefination for the Formation of C–C Bonds from Alcohols
作者:Phillip J. Black、Michael G. Edwards、Jonathan M. J. Williams
DOI:10.1002/ejoc.200600070
日期:2006.10
development of an indirect three-step domino sequence for the formation of C-Cbondsfromalcohol substrates is described. An iridium-catalysed dehydrogenation of alcohol I affords the intermediate aldehyde 2. The desired C-C bond can then be formed by a facile Wittigolefination, yielding the intermediate alkene 3. In the final step the alkene is hydrogenated to afford the indirectWittig product, the
描述了从醇底物形成 CC 键的间接三步多米诺骨牌序列的成功开发。醇 I 的铱催化脱氢得到中间体醛 2。然后可以通过简单的 Wittig 烯化形成所需的 CC 键,产生中间体烯烃 3。在最后一步中,烯烃被氢化以提供间接的 Wittig 产物,即烷烃 4. 这个过程的关键是借氢的概念;在最初的脱氢步骤中除去的氢气被铱催化剂简单地借用。作为储氢器,催化剂促进 CC 键的形成,然后在最后一步返回借用的氢。在此,我们将详细介绍我们对底物和反应范围以及催化循环的局限性的研究。((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)。
Quaternary Charge-Transfer Complex Enables Photoenzymatic Intermolecular Hydroalkylation of Olefins
作者:Claire G. Page、Simon J. Cooper、Jacob S. DeHovitz、Daniel G. Oblinsky、Kyle F. Biegasiewicz、Alyssa H. Antropow、Kurt W. Armbrust、J. Michael Ellis、Lawrence G. Hamann、Evan J. Horn、Kevin M. Oberg、Gregory D. Scholes、Todd K. Hyster
DOI:10.1021/jacs.0c11462
日期:2021.1.13
Intermolecular C-C bond-formingreactions are underdeveloped transformations in the field of biocatalysis. Here we report a photoenzymatic intermolecular hydroalkylation of olefins catalyzed by flavin-dependent 'ene'-reductases. Radical initiation occurs via photoexcitation of a rare high-order enzyme-templated charge-transfer complex that forms between an alkene, α-chloroamide, and flavin hydroquinone
Carbonyl-stabilized phosphorus ylides R3PCHC(O)R‘ (R = Ph, Tol-p; R‘ = OEt, OMe, NMe2) react with the 1,5-cyclooctadiene complexes [MCl2(cod)] (M = Pt, Pd; cod = C8H12 = 1,5-cyclooctadiene) to give the monomeric cyclooctenyl complexes [MCl2C8H12CH(PR3)C(O)R‘}}]. The ylides attack in an exo fashion to give complexes which can be regarded as metalated phosphoniumsalts. Reactions involving the replacement
羰基稳定的磷化亚磷R 3 P CHC(O)R'(R = Ph,Tol- p ; R'= OEt,OMe,NMe 2)与1,5-环辛二烯配合物[MCl 2(cod)]反应( M = Pt,Pd; cod = C 8 H 12= 1,5-环辛二烯),得到单体环辛烯基配合物[MCl 2 C 8 H 12 CH(PR 3)C(O)R'}}。所述叶酸酯以外型(exo)的方式攻击,得到可以被视为金属化的salts盐的络合物。讨论了涉及用中性配体替换一个或两个氯配体的反应。配合物[PtCl 2 C报道了8 H 12 CH(PPh 3)CO 2 Me}}}和[Pt C 8 H 12 CH(PPh 3)CO 2 Me}}(py)2 ](CF 3 SO 3)2。
The Reaction of Cyclopropenethione with Carbonyl-stabilized Phosphonium Methylides to Yield 2<i>H</i>-Pyran-2-thione
The reaction of diphenylcyclopropenethione with carbonyl-stabilized triphenylphosphonium methylides (2) to yield 2H-pyran-2-thiones was studied. It was clarified that electron-releasing substituents increased the reactivity of 2.