Visible-Light-Promoted Generation of α-Ketoradicals from Vinyl-bromides and Molecular Oxygen: Synthesis of Indenones and Dihydroindeno[1,2-c]chromenes
作者:Santosh K. Pagire、Peter Kreitmeier、Oliver Reiser
DOI:10.1002/anie.201702953
日期:2017.8.28
can be converted by a visible‐light‐mediated photocascade reaction with molecular oxygen into either indenones or dihydroindeno[1,2‐c]chromenes. The one‐step process features key photochemical steps, that is, the initial activation of vinyl bromides through energy transfer to give α‐ketoradicals in a reaction with molecular oxygen, followed by α‐oxidation of an arene moiety by 6‐π electrocyclization
邻炔基化的α-溴代肉桂酸酯可通过可见光与分子氧的光级联反应转化为茚满或二氢茚并[1,2-c]色酮。一步法具有关键的光化学步骤,即通过能量转移使乙烯基溴化物初始活化,从而使其与分子氧反应生成α-酮基衍生物,然后通过6-π电环化将芳烃部分进行α-氧化,并且随后通过同一光催化剂的电子转移过程进行的羟基化反应会生成二氢茚并[1,2-c]苯并二氢萘。