An easily removable stereo-dictating group for enantioselective synthesis of propargylic amines.
We report herein a CuBr-catalyzed three-component coupling of 2-methylbut-3-yn-2-ol, aldehydes and pyrrolidine or 1,2,3,4-tetrahydroisoquinoline leading to the corresponding chiral propargylamines in excellent enantiomeric excess (91 to >99% ee) and high yields (79-95% yield). The dimethylcarbinol unit in 2-methylbut-3-yn-2-ol, which may be easily removed at the later stage to regenerate a terminal alkyne unit for further elaboration, plays a very important role in ensuring high enantioselectivity. This protocol provides easy and very general access to different terminal and non-terminal tertiary propargylic amines.
Shanghai Key Laboratory of Green Chemistry and Chemical Process, Department of Chemistry East, China Normal University, 3663 North Zhongshan Road, Shanghai 200062, P. R. China. masm@sioc.ac.cn.
Wu
W
Fan
Shengming
S
Ma
D000447:Aldehydes / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D001966:Bromine / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D015394:Molecular Structure; D010293:Pargyline / Q000031:analogs & derivatives* / Q000737:chemistry; D011437:Propylamines / Q000737:chemistry*; D011759:Pyrrolidines / Q000737:chemistry; D013237:Stereoisomerism
D000447:Aldehydes; D000480:Alkynes; D000588:Amines; D011437:Propylamines; D011759:Pyrrolidines; C009054:propargylamine; D003300:Copper; D010293:Pargyline; C032519:pyrrolidine; D001966:Bromine