立体选择性炔烃半氢化是制备烯烃的有吸引力的方法,烯烃是合成的关键组成部分。对于最具原子经济性的还原剂二氢(H 2 ),仅公开了少数用于具有挑战性的E-选择性炔烃半氢化的催化剂,每种催化剂都具有独特的底物范围特征。在这里,我们表明,市售的镍催化剂促进了多种取代内炔的E-选择性炔烃半氢化。这产生了一个简单且广泛适用的整体方案,用于使用 H 2立体选择性地访问E-烯烃,这可以作为通用的合成方法。
Active pyrylium intermediates are in situ generated by a Rh-catalyzed vinylic C–H annulation reaction between exocyclic α,β-enones and alkynes, which undergo a base-promoted rearrangement via 1,5-H shift to form 1H-benzo[f]chromenederivatives.
活性吡啶鎓中间体是通过环外α,β-烯酮和炔烃之间的Rh催化乙烯基C–H环合反应原位生成的,环化反应通过1,5-H移位进行碱促进的重排,形成1 H-苯并[ f ] chromene衍生物。
Visible-Light-Promoted Click [3+2] Cycloaddition of Aziridine with Alkyne: An Efficient Synthesis of Dihydropyrrolidine
作者:Ritu Kapoor、I. R. Siddiqui、Ruchi Chawla、Ankit Verma、Twinkle Keshari
DOI:10.1055/a-2099-6309
日期:2023.8
A photocatalytic [3+2] cycloaddition of aziridines with activated alkynes is reported under visible-light irradiation in the presence of ruthenium catalyst. This chemical transformation provides polysubstituted pyrrolidines in good yields based on the click chemistry philosophy. The reaction successfully represents a primary trial of cyclocarboamination through photocascade catalysis combining energy