Chen BL, Wang B, Lin GQ. Highly diastereoselective addition of alkynylmagnesium chlorides to N-tert-butanesulfinyl aldimines: a practical and general access to chiral alpha-branched amines.
J Org Chem 2010;
75:941-4. [PMID:
20041724 DOI:
10.1021/jo902424m]
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Abstract
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.
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