A General Synthetic Route to 6,6-Substituted-6H-dibenzo[b,d]pyrans from Dibenzofuran
摘要:
The reaction of dibenzofuran 1, lithium pieces (2.2 equiv), and TMEDA (2.2 equiv) in dry ether under reflux led to a solution of the corresponding C, O-dilithiated intermediate 2 which, upon treatment with different ketones or aldehydes (0.8 equiv) at -78 degrees C, afforded, after hydrolysis and dehydration, 6,6-substituted-6H-dibenzo[b,d]pyrans 3 in good yields. The reaction undergoes reductive ring opening and cyclization, and the intermediate diol 4e was isolated.
Photocatalytic dehydrogenated etherification of 2-aryl benzylic alcohols
作者:Zhihui Liang、Chao Liu、Jiajun Fan、Mingze Wang、Xuanyu Yan、Mingqiang Huang、Shunyou Cai
DOI:10.1039/d2gc02030k
日期:——
we describe an efficient and practical method for the conversion of 2-aryl benzylic alcohols into the corresponding chromenes through visible-light-induced photoredox catalysis. This protocol has been applied to a wide range of benzylic alcohols, involving pharmaceuticals and natural products, with the synergistic interactions of 2-bromoanthraquinone, O2, nBu4NBr and K2CO3 in EtOH under visible-light
在这里,我们描述了一种通过可见光诱导的光氧化还原催化将 2-芳基苯甲醇转化为相应色烯的有效且实用的方法。该协议已应用于广泛的苯甲醇,包括药物和天然产物,在可见光照射下,2-溴蒽醌、O 2、n Bu 4 NBr 和 K 2 CO 3在 EtOH 中具有协同作用。该协议在结构复杂的 6 H-苯并[ c ]色烯合成中的后期应用证明了其合成效用。