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。
Catalyst Controlled Regiodivergent Arylboration of Dienes
作者:Stephen R. Sardini、M. Kevin Brown
DOI:10.1021/jacs.7b05477
日期:2017.7.26
A method for the regiodivergent arylboration of dienes is presented. These reactions allow for the formation of a diverse range of synthetically versatile products from simple precursors. Through mechanistic studies, these reactions likely operate by initial addition of a Cu-Bpin complex across the diene followed by Pd-catalyzed cross coupling with an aryl halide or pseudohalide.
Catalytic (3+2) Palladium‐Aminoallyl Cycloaddition with Conjugated Dienes
作者:Barry M. Trost、Zhongxing Huang
DOI:10.1002/anie.201900693
日期:2019.5.6
application of tailored aminoallyl precursors for catalytic (3+2) cycloaddition with conjugateddienes via a Pd‐aminoallyl intermediate. The new cycloaddition reactions override the conventional (4+3) selectivity of aminoallyl cation cycloaddition through a sequence of Pd‐allyl transfer and ring closure. A variety of highly substituted or fused pyrrolidine rings were synthesized using the cycloaddition, and can
Three‐Component Difunctionalization of Cyclohexenyl Triflates: Direct Access to Versatile Cyclohexenes via Cyclohexynes
作者:Seoyoung Cho、E. J. McLaren、Qiu Wang
DOI:10.1002/anie.202109482
日期:2021.12.6
dicarbofunctionalization, aminohalogenation and aminocarbonation of readily available cyclohexenyl triflates, via strained cyclic alkyne intermediates generated in situ. The importance and utility of this method is exemplified by the modularity of this approach and the ease in which even highly complex polycyclic scaffolds can be accessed in one step.
Competitive Reactions of Diene Cation Radicals Formed on Irradiated Metal Oxide Surfaces
作者:Marye Anne Fox、Debra D. Sackett、Janet N. Younathan
DOI:10.1016/s0040-4020(01)90277-7
日期:1987.1
which involves the intermediacy of a diene cationradical generated by transfer of an electron from the adsorbed diene to a photogenerated hole localized at the surface of the excited TiO2 particle. Non-oxidative cleavage products are also observed, and the effect of the semiconductor surface in controlling reactivity of the photogenerated cationradical is discussed. The first examples of aromatization