Engaging Allene-Derived Zwitterions in an Unprecedented Mode of Asymmetric [3+2]-Annulation Reaction
作者:Muthukumar G. Sankar、Miguel Garcia-Castro、Christopher Golz、Carsten Strohmann、Kamal Kumar
DOI:10.1002/anie.201603936
日期:2016.8.8
addition of chiral phosphine, that is, (R)‐ or (S)‐SITCP, to an α‐substituted allene ester generated a zwitterionic dipole. Under optimized reaction conditions, this dipole could engage isatine‐derived N‐Boc‐ketimines in a novel mode of [3+2] annulationreaction. Pyrrolinyl spirooxindoles are thus afforded in high yields and with excellent enantioselectivities. The unprecedented annulationreaction successfully
An enzymatic decarboxylative aldol reaction was developed for the synthesis of noncanonical α-amino acids containing γ-tertiary alcohol groups. The modularity of the electrophile enabled access to four classes of ncAAs with high efficiency as well as excellent regioselectivity and stereoselectivity.