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。
Lewis Acids Promoted 3 + 2 Cycloaddition of Oxaziridines and Cyclic Allylic Alcohols through Carbonyl Imine Intermediates
作者:Erbao Zhao、Feilong Zhou、Yujun Zhao
DOI:10.1021/acs.joc.9b00246
日期:2019.4.5
Syntheses of isoxazolidines through the carbonyl imine intermediates are currently limited to monosubstituted olefin substrates. Herein, we reported syntheses of novel bicyclic isoxazolidine-containing compounds through 1,3-dipolar cycloaddition reactions using cyclic allylicalcohols as substrates, which proved challenging in previous reports. Generally, the reaction yields range from good to high
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
The electrophilic cyanation of allylic boranes, a process that is applicable to the construction of allylic quaternary carbon centers, is reported. The reaction has a broad substrate scope with a high functional group tolerance. The results represent an unprecedented and powerful tool for preparing synthetically useful β,γ-unsaturated nitriles, including derivatives that have been difficult to access