Catalytic asymmetric ring opening of 2,3-substituted norbornenes with organometallic reagents: a new formal aza functionalization of cyclopentadiene.
An unprecedented regioselective and anti stereoselective asymmetric ring opening of 1,3-cyclopentadiene-heterodienophile cycloadducts, including also 2,3-diazabicyclo[2.2.1]heptenes, with hard alkylmetals and copper-phosphoramidite catalysts, is reported. The induced ring opening, in conjunction with C-C bond formation, gives a catalytic and practical access to new heterofunctionalized cyclopentenes in an enantioenriched form (up to 86% ee). [reaction: see text]
Pineschi
Mauro
M
Dipartimento di Chimica Bioorganica e Biofarmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy. pineschi@farm.unipi.it
Del Moro
Federica
F
Crotti
Paolo
P
Macchia
Franco
F