作者:Andreas Gansäuer、Andreas Okkel、Dennis Worgull、Gregor Schnakenburg
DOI:10.1021/om100245r
日期:2010.7.26
A modular approach to bench-stable titanocene enolates is described. The reaction of titanocenes containing pendent acid chlorides activated methylene compounds in the presence of excess base results in the formation the pivotal etiolates. In all cases, the enolates are coordinated to the titanocene, which acts as a stabilizing template in an intramolecular manner, as demonstrated by NMR spectroscopy and X-ray crystallo-graphy. Upon protonation with Strong acids, the C-C bond formed (hiring the acylation is cleaved. Hence, the template effect can be reversed by adjusting the acidity of the reaction medium.