Michael addition of stannyl ketone enolate to α, β-unsaturated esters catalyzed by tetrabutylammonium bromide and an ab initio theoretical study of the …

M Yasuda, K Chiba, N Ohigashi, Y Katoh…

Index: Yasuda, Makoto; Chiba, Kouji; Ohigashi, Noriyuki; Katoh, Yasuhiro; Baba, Akio Journal of the American Chemical Society, 2003 , vol. 125, # 24 p. 7291 - 7300

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Citation Number: 35

Abstract

Michael addition of stannyl ketone enolates to α, β-unsaturated esters was accomplished in the presence of a catalytic amount of tetrabutylammonium bromide (Bu4NBr). Other typical systems using lithium enolate or silyl enolate with catalysts (TiCl4 or Bu4NF) failed to give the desired products. The bromide anion from Bu4NBr coordinates to the tin center in enolate to accelerate the conjugate addition where a five-coordinated tin species was ...