Highly diastereoselective addition of alkynylmagnesium chlorides to N-tert-butanesulfinyl aldimines: a practical and general access to chiral alpha-branched amines.
The addition of alkynylmagnesium chlorides to N-tert-butanesulfinyl imines proceeded with a remarkably high diastereoselectivity (dr > 13:1, mostly diastereopure), and with a general scope of both reaction partners. The high dr translated into simplified purification and higher optical purity for the synthesis of a wide array of chiral alpha-branched amines. The alkyne functionality also provides a multitude of opportunities for further synthetic transformations. The short asymmetric synthesis of (+)-angustureine 7 and (-)-cuspareine 10 was realized with use of this approach.
Chen
Bai-Ling
BL
Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China.
Wang
Bing
B
Lin
Guo-Qiang
GQ
D000480:Alkynes / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D007097:Imines / Q000138:chemical synthesis* / Q000737:chemistry; D015636:Magnesium Chloride / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D000480:Alkynes; D000588:Amines; D007097:Imines; D013438:Sulfhydryl Compounds; D015636:Magnesium Chloride