Synthesis of Indolizines and Benzoindolizines by Annulation of Donor-Acceptor Cyclopropanes with Electron-Deficient Pyridines and Quinolines
作者:Nicholas A. Morra、Christian L. Morales、Barbora Bajtos、Xin Wang、Hyosook Jang、Jian Wang、Ming Yu、Brian L. Pagenkopf
DOI:10.1002/adsc.200600298
日期:2006.11
The formal [3+2] dipolar cycloaddition (or annulation) of donor-acceptor cyclopropanoate esters with pyridines and 5-nitroquinoline is reported. Electron-deficientpyridine dipolarophiles (R=CN, CO2Et, COMe) participate in the annulation whereas electron rich species do not. The product 2,3-dihydroindolizines undergo rapid autooxidation, and the X-ray structures for two of the aromatic products are