In this study, a novel asymmetricsynthesis of all-carbon quaternary stereogeniccentres is developed by the connection of three prochiral or achiral components--conjugated enones, organometallic compounds and vinyl esters--at the...
an efficient asymmetric denitrogenative cycloaddition of benzotriazoles with cyclic and acyclic 1,3-dienes enabled by Pd and chiral sulfonamide phosphine ligand. A variety of substituted hexahydrocarbazoles and indolines were delivered in good yields with high ee values. Interestingly, a pair of enantiomers could be obtained with the use of Xu1 and PC2 with the same absolute configuration. The synthetic
不对称脱氮环加成已成为构建手性氮杂杂环的有力工具。然而,迄今为止,仅探索了苯并三唑与不饱和烃的不对称脱氮环加成的一个例子,因为苯并三唑开环生成α-亚氨基金属类卡宾是一种热力学不利的过程。我们在此报告了由 Pd 和手性磺酰胺膦配体实现的苯并三唑与环状和非环状 1,3-二烯的有效不对称脱氮环加成反应。各种取代的六氢咔唑和二氢吲哚均以良好的收率和高 ee 值交付。有趣的是,使用Xu1和PC2可以获得一对对映异构体具有相同的绝对配置。还展示了光学活性六氢咔唑的合成效用。
Pt-Catalyzed Oxidative Rearrangement of Cyclic Tertiary Allylic Alcohols to Enones Using Aqueous Hydrogen Peroxide
作者:Takashi Nagamine、Yoshihiro Kon、Kazuhiko Sato
DOI:10.1246/cl.2012.744
日期:2012.7.5
An oxidative rearrangement of cyclic tertiary allylic alcohols to β-disubstituted α,β-unsaturated ketones by Pt black catalyst with aqueous hydrogen peroxide is described. The reaction proceeds under organic solvent- and halide-free conditions and gives only water as a coproduct. The Pt black catalyst is commercially available and can be reused at least four times.
Migratory Dynamic Kinetic Resolution of Carbocyclic Allylic Alcohols
作者:Chicco Manzuna Sapu、Tamás Görbe、Richard Lihammar、Jan-E. Bäckvall、Jan Deska
DOI:10.1021/ol502979g
日期:2014.11.21
isomerization/racemization catalyst gives rise to carbocyclic allylic esters with excellent stereoselectivity from readily available tertiary carbinols. An easy-to-use teabag setup combining resin-bound catalysts, a biphasic isooctane–water solvent system, and a highly lipophilic acyl donor efficiently suppresses side reactions and allows for the preparation of functionalized carbocyclic building blocks in high yields
Boronic Acid Catalyzed Friedel−Crafts Reactions of Allylic Alcohols with Electron-Rich Arenes and Heteroarenes.
作者:J. Adam McCubbin、Hamidreza Hosseini、Oleg V. Krokhin
DOI:10.1021/jo9023073
日期:2010.2.5
allylic alcohols with a variety of electron-rich aromatic and heteroaromatic substrates under ambient conditions. The commercially available catalyst is recoverable and air and moisture stable, and the reaction produces water as the only byproduct.