A Simple, Modular Method for the Synthesis of 3,4,5-Trisubstituted Pyrazoles
作者:Mark McLaughlin、Karen Marcantonio、Cheng-yi Chen、Ian W. Davies
DOI:10.1021/jo800321p
日期:2008.6.1
approach for the regiocontrolled preparation of pyrazoles bearing substituents on all three carbon atoms is described. Central to this method is the use of a switchable metal-directing group (MDG) to enable sequential direct lithiation of the 3- and 5-positions of the pyrazole ring. Pyrazole boronic esters obtained from these lithiated intermediates can undergo efficient Suzuki cross-coupling under