N-Heterocyclic Carbene-Catalyzed Cross-Coupling of Aromatic Aldehydes with Activated Alkyl Halides
摘要:
N-Heterocyclic carbene-catalyzed umpolung of aldehydes followed by their interception with diarylbromomethanes has been reported. This conceptually novel transition-metal-free cross-coupling of aldehydes with alkyl halides works well at low catalyst loadings and under mild reaction conditions leading to the formation of diaryl acetophenone derivatives in good yields. In addition, a-halo ketones and esters can also be used, as aldehyde reaction partners.
Divergent Functionalization of Alkynes Enabled by Organic Photoredox Catalysis
作者:David A. Nicewicz、Zhengbo Zhu、Siran Qian
DOI:10.1055/a-2009-8279
日期:——
oxidative conditions is challenging, as alkynes are usually recalcitrant towards typical oxidants. Herein, we communicate a strategy for the divergent functionalization of alkynes with photoexcited acridinium organic dyes, presumably via the formation of vinyl cation radicals as key intermediates. Based on the nature of the nucleophiles, different types of difunctionalized products were obtained in moderate