Premium
A New Type of Donor–Acceptor Cyclopropane Reactivity: The Generation of Formal 1,2‐ and 1,4‐Dipoles
Author(s) -
Novikov Roman A.,
Tarasova Anna V.,
Korolev Victor A.,
Timofeev Vladimir P.,
Tomilov Yury V.
Publication year - 2014
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.201306186
Subject(s) - cyclopropane , reactivity (psychology) , ylide , annulation , chemistry , acceptor , dipole , stereochemistry , medicinal chemistry , photochemistry , ring (chemistry) , organic chemistry , catalysis , physics , medicine , alternative medicine , pathology , condensed matter physics
A new type of donor–acceptor cyclopropane reactivity has been discovered. On treatment with anhydrous GaCl 3 , they react as sources of even‐numbered 1,2‐ and 1,4‐dipoles instead of the classical odd‐numbered 1,3‐dipoles due to migration of positive charge from the benzyl center. This type of reactivity has been demonstrated for new reactions, namely, cyclodimerizations of donor–acceptor cyclopropanes that occur as [2+2]‐, [3+2]‐, [4+2]‐, [5+2]‐, [4+3]‐, and [5+4]‐annulations. The [4+2]‐annulation of 2‐arylcyclopropane‐1,1‐dicarboxylates to give polysubstituted 2‐aryltetralins has been developed in a preparative version that provides exceedingly high regio‐ and diastereoselectivity and high yields. The strategy for selective hetero‐combination of donor–acceptor cyclopropanes was also been developed. The mechanisms of the discovered reactions involving the formation of a comparatively stable 1,2‐ylide intermediate have been studied.