N‐phthalimidyl, benzamidyl, acetamidyl, carbamoyl, and ureayl derivatives of dihydropyridines and the application of these reagents as precursors for N‐centered radicals are presented. These aminated dihydropyridines could be used in radical‐transferhydroamination reactions of various electron‐rich as well as nonactivated olefins in the presence of thiols as polarity‐reversal catalysts. These reactions
Tuning the Reactivity of Alkoxyl Radicals from Cyclization to 1,2-Silyl Transfer: Stereoselective Synthesis of β-Substituted Cycloalcohols
作者:Xingyi He、Yunlong Zhao、Zeguo Zhang、Xiao Shen
DOI:10.1021/acs.orglett.2c00428
日期:2022.3.18
Herein, we report a radical strategy for diastereoselective construction of β-substituted cyclopentanols and cyclobutanols. The success of the reaction is attributed to the favorable radical 1,2-silyl transfer over the cyclization of alkoxy radicals to the olefins. The reaction shows broad substrate scope and wide functional-group tolerance. The synthetic potential of the methodology was demonstrated
pyrazoleamides with silylenolethers was realized by employing a chiral N,N'-dioxide-Ni(II) complex catalyst. The process includes the formation of chiral nickel carbenoid intermediate and the following enantioselective cycloaddition reaction. The desired dihydrofuran O,O-acetal derivatives were obtained in good yields (up to 90%) with high enantioselectivity (up to 99% ee) under mild reaction conditions within
通过使用手性N,N'-二氧化物-Ni(II) 络合物催化剂,实现了α-重氮吡唑酰胺与甲硅烷基烯醇醚的高效不对称 (3 + 2) 环加成反应。该过程包括手性镍类胡萝卜素中间体的形成和随后的对映选择性环加成反应。在温和的反应条件下,在短反应时间内,以高对映选择性(高达 99% ee )获得了所需的二氢呋喃O,O-缩醛衍生物(高达 90%)。在确定催化剂结构的基础上,提出了一种可能的过渡态模式。
Thiol-Catalyzed Stereoselective Transfer Hydroamination of Olefins with N-Aminated Dihydropyridines
作者:Joyram Guin、Roland Fröhlich、Armido Studer
DOI:10.1002/anie.200703902
日期:2008.1.11
Enantioselective Cobalt‐Catalyzed Hydroboration of Ketone‐Derived Silyl Enol Ethers
作者:Wenke Dong、Zhiyang Ye、Wanxiang Zhao
DOI:10.1002/anie.202117413
日期:2022.7.18
heteroatom-substituted alkenes is rarely explored and remains unprecedented, especially the earth-abundant metal catalyzed ones. Herein, the first cobalt-catalyzed asymmetric hydroboration of ketone-derived silylenolethers is reported, providing a convenient approach to access valuable enantiopure β-hydroxy boronic esters, which features broad substrate scope and excellent enantioselectivities.