A Comparative Investigation: Group 9 Cp*M(III)-Catalyzed Formal [4 + 2] Cycloaddition as an Atom-Economic Approach to Quinazolines
作者:Xiaoming Wang、Andreas Lerchen、Frank Glorius
DOI:10.1021/acs.orglett.6b00716
日期:2016.5.6
A comparative study on the catalytic activity of different group 9 [Cp*M(III)] complexes in the formal [4 + 2] cycloaddition of arenes with rarely explored free imines and dioxazolones for the construction of multisubstituted quinazolines is reported herein. This investigation revealed that the cobalt catalyst is uniquely suited to this transformation due to its strong Lewis acidity and high sensitivity
The first lithiation on the benzene moiety of 4-substituted quinazolines has been highlighted. According to the nature and position of various directing groups, an exceptional regioselective metallation occured at position C8, peri to the N-1 ring nitrogen. This method allows an easy access to a large range of new substituted quinazolines.