Sequential C–H and C–C Bond Cleavage: Divergent Constructions of Fused <i>N</i>-Heterocycles via Tunable Cascade
作者:Xianwei Li、Jianhang Rao、Wensen Ouyang、Qian Chen、Ning Cai、Yu-Jing Lu、Yanping Huo
DOI:10.1021/acscatal.9b03091
日期:2019.9.6
multiple cascade reactions for the divergent assembly of fused N-heterocycles, comprising sequential activation of C–H and C–C bonds. Isolatable indene-type intermediates might be responsible for the generation of densely substituted fused pyridines, azepines, and azafluorenones products. The tolerance of stronglycoordinatingN-heterocycles, and those readily applicable for the late-stage modifications
An efficient approach for the synthesis of unsymmetrical and symmetrical multi-substituted pyridines is demonstrated. This process is preceded via iron−catalysed [3+3] annulation of oxime acetates with enaminones. Operational simplicity, use of easily available starting materials and inexpensive catalyst, avoiding the use of additives or ligands are the major advantages of this protocol.