American Chemical Society
cs300751a_si_002.pdf (2 MB)

Phosphine-Catalyzed [3 + 2] Cycloaddition of 4,4-Dicyano-2-methylenebut-3-enoates with Benzyl Buta-2,3-dienoate and Penta-3,4-dien-2-one

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journal contribution
posted on 2013-04-05, 00:00 authored by Xiao-Nan Zhang, Min Shi
4,4-Dicyano-2-methylenebut-3-enoates are employed in the phosphine-catalyzed [3 + 2] cycloaddition with allenoates for the first time, affording regiospecific [3 + 2]-annulation products in moderate to good yields. The multifunctional chiral thiourea-phosphines having an axially chiral binaphthyl scaffold are effective catalysts for the asymmetric variant of this reaction, giving the α-regioisomers in good yields and moderate enantioselectivities.