Asymmetric Methallylation of Ketones Catalyzed by a Highly Active Organocatalyst 3,3′-F2-BINOL
摘要:
(S)-3,3'-F-2-BINOL has been synthesized for the first time and demonstrated as a highly active organocatalyst for asymmetric methallylation of ketones. Up to 98:2 enantioselectivity and 99% yield were obtained with 5 mol % catalyst loading. The catalyst (S)-3,3'-F-2-BINOL could be easily recovered and reused.
Herein we disclose an asymmetric allylation of 3-hydroxyisobenzofuran-1(3H)-ones with boron allylation reagents to construct chiral phthalide derivatives. The simple Bi(OAc)3/chiral phosphoricacid catalytic system proves to be efficient in this method, delivering the desired chiral 3-allylisobenzofuran-1(3H)-ones in good yields (up to 99%) and high enantioselectivities (up to 99.5:0.5 e.r.) under mild
Full chirality transfer in the synthesis of hindered tertiary boronic esters under in situ lithiation–borylation conditions
作者:D. J. Blair、S. Zhong、M. J. Hesse、N. Zabaleta、E. L. Myers、V. K. Aggarwal
DOI:10.1039/c6cc00536e
日期:——
Using non-cryogenic lithiation-borylation, sterically hindered tertiary neopentyl glycol boronicesters can be prepared from secondary benzylic carbamates with full chirality transfer.
使用非低温锂化-硼酸化,可以从具有完全手性转移的仲苄基氨基甲酸酯制备位阻叔新戊二醇硼酸酯。
Catalytic enantioselective allylboration of propargylic aldehydes
作者:Urmibhusan Bhakta、Erin Sullivan、Dennis G. Hall
DOI:10.1016/j.tet.2013.11.095
日期:2014.1
Homoallylic propargylicalcohols are important building blocks in natural product synthesis. This moiety can be transformed into various other structures by performing other known transformations, which can in turn lead to the synthesis of biologically useful compounds. Herein, a methodology based on Lewisacid assisted Brønstedacid catalysed allylboration of propargylic aldehydes is described. A
Enantioselective allylation of aldehydes and ketones is a widely used approach for preparing chiral homoallylic alcohols, however, most of the reactions are still mainly performed in organic solvents. Considering their environmental impact, expansion of synthetic technology in water has the highest priority in the organic chemistry field. Here, we report enantioselective reaction of water‐stable amido‐functionalized
A general and mostly highlystereoselective method for effective synthesis of 1-boryl-3-(silyl)propenes via one-step catalytic processes, i.e. silylative coupling of vinylsilanes with allyl boronates, borylative coupling of vinyl boronates with allylsilanes catalysed by [RUHCl(CO)(PCy 3 ) 2 ] and cross-metathesis of respective derivatives in the presence of Grubbs catalysts, is described.