Synergistic Catalysis by Brønsted Acid/Carbodicarbene Mimicking Frustrated Lewis Pair‐Like Reactivity
作者:Yi‐Chen Chan、Yuna Bai、Wen‐Ching Chen、Hsing‐Yin Chen、Chen‐Yu Li、Ying‐Yann Wu、Mei‐Chun Tseng、Glenn P. A. Yap、Lili Zhao、Hsuan‐Ying Chen、Tiow‐Gan Ong
DOI:10.1002/anie.202107127
日期:2021.9
Carbodicarbene (CDC), unique carbenic entities bearing two lone pairs of electrons are well-known for their strong Lewis basicity. We demonstrate herein, upon introducing a weak Brønstedacid benzyl alcohol (BnOH) as a co-modulator, CDC is remolded into a Frustrated Lewis Pair (FLP)-like reactivity. DFT calculation and experimental evidence show BnOH loosely interacting with the binding pocket of CDC
Ruthenium catalyzed selective hydrosilylation of aldehydes
作者:Basujit Chatterjee、Chidambaram Gunanathan
DOI:10.1039/c3cc47593j
日期:——
A chemoselective hydrosilylation method for aldehydes is developed using a ruthenium catalyst [(Ru(p-cymene)Cl2)2] and triethylsilane; a mono hydride bridged dinuclear complex [(η6-p-cymene)RuCl}2(μ-H-μ-Cl)] and a Ru(IV) mononuclear dihydride complex [(η6-p-cymene)Ru(H)2(SiEt3)2] are identified as potential intermediates in the reaction and the proposed catalytic cycle involves a 1,3-hydride migration.
heterolytic activation of the Si–H bond. The molecular structure of a new example of such an adduct was resolved by X-ray diffraction analysis. Theoretical considerations support a donor–acceptor [C,N}Cp*IrIII-H]→[SiEt3]+ (C,N} = benzo[h]quinolinyl) formulation where the cationic silyl moiety acting as a Z ligand binds both Ir and H centers. Under the conditions of the catalysis, the latter adduct is assumed
合成了含有(五甲基环戊二烯基)铱(III)单元的一组iridacycles [C,N} Cp * Ir III -Cl](C,N} =苯并[ h ]喹啉,二苯并[ f,h ]喹啉)并衍生为与BArF型阴离子缔合的阳离子[C,N} Cp * Ir-NCMe] +。后者的盐因其在H 2中对HSiEt 3的潜在催化性能而进行了基准测试-释放测试反应。表现最佳的BArF型盐显示出能够以低的催化负载量(大约)促进反应的能力。乙腈,丙腈和一系列芳腈底物的自动串联氢化硅烷化为0.5–1 mol%。机理研究证实,Si-H键的亲电和杂合活化可初步形成硅烷-铱环加合物。通过X射线衍射分析解析了这种加合物的新实例的分子结构。理论上的考虑支持了施主-受主[C,N} Cp * Ir III -H]→[SiEt 3 ] +(C,N} =苯并[ h ]喹啉基)的配方,其中阳离子甲硅烷基部分充当Z配体结合Ir和
Carbonyl and olefin hydrosilylation mediated by an air-stable phosphorus(<scp>iii</scp>) dication under mild conditions
作者:Ryan J. Andrews、Saurabh S. Chitnis、Douglas W. Stephan
DOI:10.1039/c9cc02460c
日期:——
The readily-accessible, air-stable Lewis acid [(terpy)PPh][B(C6F5)4]21 is shown to mediate the hydrosilylation of aldehydes, ketones, and olefins. The utility and mechanism of these hydrosilylations are considered.
已显示出易于获得的,空气稳定的路易斯酸[(terpy)PPh] [B(C 6 F 5)4 ] 2 1可介导醛,酮和烯烃的氢化硅烷化。考虑了这些氢甲硅烷基化的效用和机理。