Formation of oxasilacyclopentenes from carbonyls and alkynylsilanes: An investigation of reaction scope and mechanism

ORGN 528

Sarah V Maifeld and Daesung Lee, dlee@chem.wisc.edu. Department of Chemistry, University of Wisconsin, 1101 University Ave, Madison, WI 53706
Oxasilacyclopentenes, which serve as useful intermediates in organic synthesis, were efficiently produced in a one-step reaction from carbonyls and alkynylsilanes in the presence of a catalytic amount of metal alkoxide. The reaction proceeds readily at room temperature and is tolerant of a wide variety of carbonyl substrates; however, only small variations in the steric and stereoelectronic environment on the alkynylsilane are permitted. Mechanistic aspects and parameters that influence the efficiency of the reaction, such as the substituents on the silyl and alkynyl groups as well as the metal alkoxide, will be discussed. Overall, the transformation represents a one-pot synthesis of cyclic vinylsilane-containing silyl ethers via a novel tandem alkynylation-hydrosilylation.