An Intramolecular Titanium-Catalyzed Asymmetric Pauson−Khand Type Reaction<sup>1</sup>
作者:Frederick A. Hicks、Stephen L. Buchwald
DOI:10.1021/ja990683m
日期:1999.8.1
The development of the first catalytic asymmetric Pauson−Khandtype cyclization of enynes is described. The active catalyst, (S,S)-(EBTHI)Ti(CO)2 (1), is generated in situ from (S,S)-(EBTHI)TiMe2 (2). A variety of 1,6-enynes can be converted to the corresponding cyclopentenones in high yield (70−94%) with excellent ee's (87−96%). Limitations of the catalyst with respect to substrate structure are discussed