Asymmetric synthesis in aqueous solvents using chimeric peptide catalysts

通过2D-核磁共振测量发现，嵌合肽催化剂中看似不具有催化活性的螺旋部分起到了稳定催化活性转折基序的作用。用组合方法筛选了最佳的多肽催化剂，找到了一个序列未知的多肽。预计新发现的多肽催化剂可能不是通过简单的空间控制而是通过其他指导原则来实现对映体的选择性。对于嵌合肽催化的其他反应，1)与β-二取代α，β-不饱和醛的共轭加成反应和2)外消旋平面手性化合物的动力学拆分被成功地开发出来。

The seemingly not catalytically active helical part of the chimeric peptide catalyst was found to play a role to stabilize the catalytically active turn motif by means of 2D-NMR measurement. Screening for optimal peptide catalyst was performed on the basis of combinatorial approach, and a peptide with hitherto unknown sequence was found. It was anticipated that the newly found peptide catalyst might realize the enantioselectivity not by simple steric control but by other guiding principle. For other reactions catalyzed by chimeric peptides, 1) a conjugate addition to beta-disubstituted alpha,beta-unsaturated aldehydes and 2) kinetic resolution of racemic planar chiral compounds were successfully developed.