Enantioselective one-pot three-component synthesis of propargylamines catalyzed by copper(I)–pyridine bis-(oxazoline) complexes |
| |
Authors: | Alakesh Bisai Vinod K Singh |
| |
Institution: | 1. Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, UP, India;2. Department of Chemistry, Indian Institute of Science Education and Research Bhopal, ITI (Gas Rahat) Building, Govindpura, Bhopal 462 023, MP, India |
| |
Abstract: | A one-pot three-component coupling of aldehydes and amines in presence of terminal alkynes has been efficiently catalyzed by copper (I) complex of i-Pr-pybox-diPh 2b or s-Bu-pybox-diPh 2c. The process is simple and allows the synthesis of various propargylamines in good to excellent enantioselectivities (up to 99% ee) and in higher yields. The nature of the substituents attached to imines plays a vital role on the enantioselectivities obtained. The presence of gem-diphenyl group at C-5 position and secondary alkyl substituents at the C-4 chiral center of the oxazoline rings of the chiral ligands was found to be crucial for higher enantioselectivities. A transition state model involving π–π stacking is also proposed for the stereochemical outcome. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|