Selectivity Control in Lewis Acid Catalyzed Regiodivergent Tandem Cationic Cyclization/Ring Expansion Terminated by Pinacol Rearrangement
作者:Lu Liu、Junliang Zhang
DOI:10.1002/anie.200901628
日期:2009.8.3
Catalyst is key: The title reaction sequence has been carried out on 1 in the presence of AgSbF6 (5 mol %) in DCE or In(OTf)3 (5 mol %) with MeOH (4 equiv) to afford 2 or 3, respectively, in up to >20:1 ratio (see scheme; DCE=1,2‐dichloroethane, Tf=trifluoromethanesulfonyl).
催化剂是关键:标题反应顺序是在AgSbF 6(5 mol%)在DCE或In(OTf)3(5 mol%)与MeOH(4当量)的存在下于1进行的,得到2或3,分别以大于20:1的比例(请参阅方案; DCE = 1,2-二氯乙烷,Tf =三氟甲磺酰基)。