extensive but non-recyclable use of tetraalkoxydiboron(4) compounds as stoichiometric reagents in diverse reactions, this article reports an atom-economical reaction using a commercial diboron(4) as the catalyst. The key to success was designing a catalytic cycle for radical [3 + 2] cycloaddition involving a pyridine cocatalyst to generate from the diboron(4) catalyst and reversibly mediate the transfer of
Selective [2σ + 2σ] Cycloaddition Enabled by Boronyl Radical Catalysis: Synthesis of Highly Substituted Bicyclo[3.1.1]heptanes
作者:Tao Yu、Jinbo Yang、Zhijun Wang、Zhengwei Ding、Ming Xu、Jingru Wen、Liang Xu、Pengfei Li
DOI:10.1021/jacs.2c13740
日期:——
2σ] radical cycloaddition between bicyclo[1.1.0]butanes (BCBs) and cyclopropyl ketones has been developed to provide a modular, concise, and atom-economical synthetic route to substituted bicyclo[3.1.1]heptane (BCH) derivatives that are 3D bioisosteres of benzenes and core skeleton of a number of terpene natural products. The reaction was catalyzed by a combination of simple tetraalkoxydiboron(4) compound
Photocatalytic Regioselective [2 + 2 + 1] Radical Annulation of Alkenes with <i>tert</i>-Butyl Nitrite and <i>gem</i>-Dihalides
作者:Jiupeng Liu、Shuo Tang、Huayan Xu、Ruoyu Zhang、Jingjing Zhao、Puyu Zhang、Pan Li
DOI:10.1021/acs.orglett.2c03635
日期:2022.12.30
A visible-light photocatalytic regioselective [2 + 2 + 1] radical annulation reaction of alkenes, tert-butyl nitrite, and gem-dihalides has been developed. The protocol provides an efficient and practical approach to obtain isoxazolines in good yields under mild conditions. Significantly, gem-dihalides serve as C1 synthons, while cheap tert-butyl nitrite acts as an ideal “N–O” synthon.
hydroacylation of cyclopropene is disclosed for synthesizing various 2-acylcyclopropane derivatives under mild reaction conditions. High functional group tolerance of this protocol features a novel route to access a divergent synthesis of acylated cyclopropane in a diastereoselective manner by photoinduced decarboxylation of α-ketoacid followed by acyl radical addition to cyclopropene. Additionally, the
Privileged chiral catalysts—those that share common structural features and are enantioselective across a range of reactions—continue to transform the chemical-research landscape1. In recent years, newreactivity modes have been achieved through excited-state catalysis, processes activated by light, but it is unclear if the selectivity of ground-state privileged catalysts can be matched. Although the