Highly Efficient Asymmetric Trans-Selective Aziridination of Diazoacetamides and N-Boc-imines Catalyzed by Chiral Brønsted Acids
摘要:
A clean and fast (10 min) aziridination of diazoacetamides with N-Boc-imines, as well as N-Cbz-imines, catalyzed by chiral phosphoric acid (R)-5g in DCM at room temperature was developed, The excellent yields (89-97%), diastereoselectivities (trans/cis > 50:1), chemoselectivities (3:4 = >95:5), and enantioselectivities (88-98% ee) were achieved in the reaction.
direct and effective transformation of α-amino ketones, acetamides, and esters to the corresponding α-diazo products under mild basic conditions has been developed. This one-step synthetic approach not only allows for generation of α-substituted-α-diazo carbonyl compounds from α-amino acidderivatives but also permits preparation of α-diazo dipeptides from N-terminal dipeptides (32 examples, up to 91%)