InBr3-catalyzed reduction of ketones with a hydrosilane: deoxygenation of aromatic ketones and selective synthesis of secondary alcohols and symmetrical ethers from aliphatic ketones
An InBr3–Et3SiH reducing system was developed to selectively convert aliphatic ketones to a variety of secondary alcohols in moderate to good yields. An initial mixing of InBr3 and PhSiH3 was followed by the addition of aliphatic ketones and a solvent to afford the symmetrical ether derivatives.
The chemistry of the boron cation has been revitalized in the past decade due to its newfound application in stoichiometric and catalytic organic reactions. To extend the frontier of boron cation catalysis, we came to discover that a mesityl-substituted η5-Cp*-coordinated boron cation could serve as a powerful Lewisacid for organic catalytic transformations. The boron cation [Cp*B-Mes][B(C6F5)4] ([1][B(C6F5)4])
由于硼阳离子在化学计量和催化有机反应中的新发现,在过去的十年中,硼阳离子的化学得到了振兴。为了延长硼阳离子催化的前沿,我们来到发现一个均三甲苯基取代的η 5 -Cp *配位的硼阳离子可以作为一种强大的路易斯酸为有机催化转化。稳定在硼状电子结构中的硼阳离子[Cp * B-Mes] [B(C 6 F 5)4 ]([ 1 ] [B(C 6 F 5)4 ])易于与Et 3 PO结合,显示的受主编号超过B(C 6 F 5)3在Gutmann-Beckett酸度等级上。给电子Cp *产生的空间和电子稳定性使高路易斯酸性硼阳离子成为在环境温度下易于进行芳基酮加氢脱氧的催化剂。[ 1 ] +的出色的催化性能表明,在硼中引入配位柔性取代基对于为硼阳离子催化剂带来催化活性和稳定性至关重要。
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。
[Mes-<i>B</i>-TMP]<sup>+</sup> borinium cation initiated cyanosilylation and catalysed hydrosilylation of ketones and aldehydes
Two aryl amino borinium cations derived from Cl(Mes)B-NR2 (NR2 = TMP, HMDS) faced divergent outcomes. As the HMDS-substituted one underwent methylmigration from silicon to boron transforming the putative borinium ion to a silylium ion, [Mes-B-TMP]+ can initiate cyanosilylation and catalyse hydrosilylation of ketones and aldehydes.
Silyl formates as hydrosilane surrogates for the transfer hydrosilylation of ketones
作者:R. Martin Romero、Neethu Thyagarajan、Nora Hellou、Clément Chauvier、Timothé Godou、Lucile Anthore-Dalion、Thibault Cantat
DOI:10.1039/d2cc00666a
日期:——
A transfer hydrosilylation of ketones employing silyl formates as hydrosilane surrogates under mild conditions is presented. A total of 24 examples of ketones have been successfully converted to their corresponding silyl ethers with 61–99% yields in the presence of a PNHP-based ruthenium catalyst and silyl formate reagent. The crucial role of the ligand for the transformation is demonstrated.
介绍了在温和条件下使用甲硅烷基甲酸酯作为氢化硅烷替代物的酮的转移氢化硅烷化。在 PN H P 基钌催化剂和甲酸甲硅烷酯试剂存在下,共有 24 个酮类实例成功地转化为相应的甲硅烷基醚,产率为 61-99% 。证明了配体对转化的关键作用。