Premium
Engaging Allene‐Derived Zwitterions in an Unprecedented Mode of Asymmetric [3+2]‐Annulation Reaction
Author(s) -
Sankar Muthukumar G.,
GarciaCastro Miguel,
Golz Christopher,
Strohmann Carsten,
Kumar Kamal
Publication year - 2016
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201603936
Subject(s) - allene , annulation , chemistry , phosphine , combinatorial chemistry , catalysis , medicinal chemistry , stereochemistry , organic chemistry
Catalytic 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] annulation reaction. Pyrrolinyl spirooxindoles are thus afforded in high yields and with excellent enantioselectivities. The unprecedented annulation reaction successfully facilitated the construction of sp 3 ‐rich and highly substituted 3,2′‐pyrrolidinyl spirooxindoles supporting many chiral centers.