Michael-cross-benzoin cyclisation

Michael-cross-benzoin cyclisation reaction afforded the corresponding chiral polyfunctionalised cyclopentanones bearing three contiguous stereocentres in good yields, moderate to excellent diastereoselectivities of up to 98% de, and good to high enantioselectivities of up to 96% ee, as shown in Scheme 2.31. 

Scheme 2.31 Tandem Michael-cross-benzoin cyclisation reaction catalysed by a chiral diarylprolinol trimethylsilyl ether and an Af-heterocyclic carbene.

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