Reversible Silylium Transfer between P‐H and Si‐H Donors
作者:Roman G. Belli、Dimitrios A. Pantazis、Robert McDonald、Lisa Rosenberg
DOI:10.1002/anie.202011372
日期:2021.2
The Mo=PR2 π* orbital in a Mo phosphenium complex acts as acceptor in a new PIII‐based Lewis superacid. This Lewisacid (LA) participates in electrophilic Si‐H abstraction from E3SiH to give a Mo‐bound secondary phosphine ligand, Mo‐PR2H. The resulting Et3Si+ ion remains associated with the Mo complex, stabilized by η1‐P‐H donation, yet undergoes rapid exchange with an η1‐Si‐H adduct of free silane in
Chemoselective Hydrosilylation of the α,β-Site Double Bond in α,β- and α,β,γ,δ-Unsaturated Ketones Catalyzed by Macrosteric Borane Promoted by Hexafluoro-2-propanol
作者:Xiao-Yu Zhan、Hua Zhang、Yu Dong、Jian Yang、Shuai He、Zhi-Chuan Shi、Lei Tang、Ji-Yu Wang
DOI:10.1021/acs.joc.0c00568
日期:2020.5.15
The B(C6F5)3-catalyzed chemoselective hydrosilylation of α,β- and α,β,γ,δ-unsaturated ketones into the corresponding non-symmetric ketones in mild reaction conditions is developed. Nearly 55 substrates including those bearing reducible functional groups such as alkynyl, alkenyl, cyano, and aromatic heterocycles are chemoselectively hydrosilylated in good to excellent yields. Isotope-labeling studies
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.
Photo Lewis acid generators: photorelease of B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> and applications to catalysis
作者:Andrey Y. Khalimon、Bryan K. Shaw、Adam J. V. Marwitz、Warren E. Piers、James M. Blackwell、Masood Parvez
DOI:10.1039/c5dt03008k
日期:——
A series of molecules capable of releasing of the strong organometallic LewisacidB(C6F5)3 upon exposure to 254 nm light have been developed. These photo Lewisacid generators (PhLAGs) can now serve as photoinitiators for several important B(C6F5)3-catalyzed reactions. Herein is described the synthesis of the triphenylsulfonium and diphenyliodonium salts of carbamato- and hydridoborates, their establishment
已经开发出了一系列能够在暴露于254 nm的光后释放出强有机金属路易斯酸B(C 6 F 5)3的分子。这些光路易斯酸产生剂(PhLAG)现在可以用作几个重要的B(C 6 F 5)3催化反应的光引发剂。本文描述了氨基甲酸酯和氢硼酸酯的三苯基s盐和二苯基碘鎓盐的合成,它们作为PhLAG的建立以及旨在确定硼烷释放机理的研究。还讨论了影响这些光解反应的因素以及该概念在光诱导的氢化硅烷化反应中的应用以及硅氧烷支架的构建。
Catalytic Hydrosilylation of Carbonyls via Re(CO)<sub>5</sub>Cl Photolysis
The hydrosilylation reaction between silanes and various carbonyl substrates such as aldehyde, ketone, ester, and carbonate has been catalyzed by Re(CO)5Cl UV photolysis. Kinetic studies have shown that the reaction is favored for the least sterically hindered silanes with aldehydes followed by aliphatic ketones. The IR spectrum of the rhenium carbonyl dimer HRe2(CO)9(SiR3) has been recorded in the
硅烷与各种羰基底物(如醛,酮,酯和碳酸酯)之间的氢化硅烷化反应已通过Re(CO)5 Cl UV光解进行了催化。动力学研究表明,对于位阻最小的硅烷与醛,其次是脂族酮,该反应是有利的。羰基rh二聚体HRe 2(CO)9(SiR 3)的红外光谱已记录在反应混合物中。该络合物被认为是活性催化剂Re(CO)4 SiR 3的静止状态。,可以在激活后释放。已经提出了涉及该物种的催化机理,并通过计算研究显示出其在热力学上是可行的。另外,可以使用相同的机理解释各种羰基底物之间的相对氢化硅烷化速率。