Rhodium-Catalyzed Cascade Oxidative Annulation Leading to Substituted Naphtho[1,8-<i>bc</i>]pyrans by Sequential Cleavage of C(sp<sup>2</sup>)–H/C(sp<sup>3</sup>)–H and C(sp<sup>2</sup>)–H/O–H Bonds
作者:Xing Tan、Bingxian Liu、Xiangyu Li、Bin Li、Shansheng Xu、Haibin Song、Baiquan Wang
DOI:10.1021/ja3075242
日期:2012.10.3
efficiently in the presence of a rhodium catalyst and a copper oxidant to give substituted naphtho[1,8-bc]pyrans by sequential cleavage of C(sp(2))-H/C(sp(3))-H and C(sp(2))-H/O-H bonds. These cascade reactions are highly regioselective with unsymmetrical alkynes. Experiments reveal that the first-step reaction proceeds by sequential cleavage of C(sp(2))-H/C(sp(3))-H bonds and annulation with alkynes