A cascade sequence between cyclic hemiacetals and tryptamines was developed, which provided efficient access to highly substituted diazaindeno[2,1-α]phenanthrenes in moderate to good yields with high diastereoselectivities and good to excellent enantioselectivities. Hemiacetals were prepared by asymmetric organocatalyzed conjugate addition of cyclic 1,3-diketones to α,β-unsaturated aldehydes. Hemiacetals
环状
半缩醛和
色胺之间的级联序列被开发出来,它提供了以中等到良好的产率,高非对映选择性和良好到优异的对映选择性有效获得高取代的二氮杂
茚并[2,1- α ]
菲的途径。通过将环状1,3-二酮不对称地有机催化共轭加成到α,β-不饱和醛上来制备
半缩醛。检查具有各种R 1(芳族和脂族)的
半缩醛的级联序列。