Diastereoselective Diels−Alder Reactions of <i>N</i>-Sulfonyl-1-aza-1,3-butadienes with Optically Active Enol Ethers: An Asymmetric Variant of the 1-Azadiene Diels−Alder Reaction
作者:Ryan C. Clark、Steven S. Pfeiffer、Dale L. Boger
DOI:10.1021/ja0571646
日期:2006.3.1
room-temperature asymmetricDiels-Alder reaction of N-sulfonyl-1-aza-1,3-butadienes is reported enlisting a series of 19 enol ethers bearing chiralauxiliaries, with many providing highly diastereoselective (endo and facial diastereoselection) reactions, largely the result of an exquisitely organized [4+2] cycloaddition transition state. Three new, readily accessible, and previously unexplored auxiliaries rationally