In the presence of 2,6-diisopropylphenol and t-BuOMe (1 equiv. each), asymmetric Mukaiyama-Michael reaction of a variety of benzalacetone derivatives 2 with silyl ketene acetal 3 is efficiently catalyzed by O-(2-naphthoyl)-N-tosyl-(L)-allo-threonine-derived B-phenyloxazaborolidinone 1 (10 mol%) to give the corresponding adducts 5 in 60-90% ee.
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