Asymmetric Diels–Alder and ene reactions promoted by a Ti(IV) complex bearing a C2-symmetric tridentate ligand
作者:G. Manickam、G. Sundararajan
DOI:10.1016/s0957-4166(99)00300-6
日期:1999.7
A new Ti(IV) complex obtained from the C2-symmetric amino diol (1R,5R)-3-aza-3-benzyl-1,5-diphenyl pentan-1,5-diol, (1R,5R)-1, is used effectively as a Lewis acid promoter in asymmetric Diels–Alder reactions. Using various Evans' oxazolidinones as dienophiles and cyclopentadiene as the diene high yields of the adducts with moderate enantioselectivity, under different reaction conditions are achieved
从C 2对称氨基二醇(1 R,5 R)-3-氮杂-3-苄基-1,5-二苯基戊丹-1,5-二醇(1 R,5 R)-1,在不对称Diels-Alder反应中有效用作路易斯酸促进剂。使用各种埃文斯恶唑烷酮作为亲二烯体和环戊二烯作为二烯,可以在不同的反应条件下以中等对映选择性高收率地形成加合物。报告了溶剂,温度和配体对Diels–Alder产品对映选择性的影响。分子模型研究提供了对Diels–Alder反应的非对面选择性的理解。还描述了各种乙醛酸酯和α-甲基苯乙烯之间的不对称羰基-烯反应。