Tin(IV) Chloride-Chiral Pyrogallol Derivatives as New Lewis Acid-Assisted Chiral Brønsted Acids for Enantioselective Polyene Cyclization
作者:Keiko Kumazawa、Kazuaki Ishihara、Hisashi Yamamoto
DOI:10.1021/ol049126h
日期:2004.7.1
[reaction: see text] New Lewis acid-assisted Bronsted acids (LBAs), tin(IV) chloride-2,6-dialkoxyphenols, serve as artificial cyclases for biomimetic polyene cyclization. For example, the enantioselective cyclization of 4-(homogeranyl)toluene using tin(IV) chloride-2,6-di[(1'R,2'R)-trans-2'-(3' ',5' '-xylyl)cyclohexanoxy]phenol gave a trans-fused tricyclic compound with 85% ee.
[反应:见正文]新型路易斯酸辅助布朗斯台德酸(LBA),氯化锡(IV)-2,6-二烷氧基苯酚,可作为人工环化酶用于仿生多烯环化。例如,使用氯化锡(IV)-2,6-di [(1'R,2'R)-trans-2'-(3'',5''- (二甲苯基)环己氧基]苯酚制得具有85%ee的反式稠合三环化合物。