Highly Selective Acetate Aldol Additions Using Mesityl-Substituted Chiral Auxiliaries
摘要:
Highly diastereoselective acetate aldol additions using chlorotitanium enolates of mesityl-substituted N-acetyloxazolidinethione and N-acetylthiazolidinethione auxiliaries are reported. These additions proceed in high yields and diastereoselectivities (93:7 to 98:2) for aliphatic, aromatic, and alpha,beta-unsaturated aldehydes. Double diastereoselective acetate aldol additions are also reported and are found to proceed in high yields and diastereoselectivities (90:10 to 97:3).
A copper-catalyzeddirect asymmetric coupling of C2 sterically-hindering-group-substituted indoles with quinone and naphthoquinone esters was developed by using the spirocyclic pyrrolidine oxazoline (SPDO) ligand, which was accomplished by metal catalysis for the first time. Diverse structures of axially chiral 3-arylindoles were obtained with good to high enantioselectivities in good to high yields