117775-76-5Relevant academic research and scientific papers
Synthesis of η1 Oxygen-Bound Rhodium Enolates. Applications to Catalytic Aldol Chemistry
Slough, Greg A.,Bergman, Robert G.,Heathcock, Clayton H.
, p. 938 - 949 (2007/10/02)
Oxygen-bound rhodium enolate complexes are prepared by metathesis of carbonylbis(phosphine)rhodium(I) halides and potassium enolates, 3-6.Rhodium enolates of acetophenone (7), propiophenone (9), ethyl mesityl ketone (10), and ethyl tert-butyl ketone (11) were prepared and fully characterized.Complex 11 condenses with benzaldehyde under a variety of conditions to produce isolable rhodium aldolate complex 12.Cleavage of 12 with trimethylsilyl chloride yields aldol silyl ether and rhodium chloride.Similar treatment of 12 with an enol silane affords the aldol silylether and a rhodium enolate.A catalytic aldol reaction involving enol silanes, silylketene acetals, and benzaldehyde under rhodium catalysis is presented.Deuterium, phosphorus, and carbon NMR were used to demonstrate the intermediacy of rhodium enolates and aldolates in the aldol process and to elucidate the gross mechanistic features of the catalytic cycle.
