Michael/aldol cascade cyclohexanones

A BINAP-derived bifunctional thiophosphoramide gives >98% del>99% ee in Michael addition of cyclohexanones to both aryl- and alkyl-substituted nitroolefins. Imidazolylmethyl ketones undergo one-pot Michael-aldol cascade reactions with Q ,/3-unsaturated aldehydes in DCM at 20 °C using the simple organocatalyst, prolinol... 

Scheme 7.15 Synthesis of polysubstituted cyclohexanones by cascade Michael/aldol reaction of P-ketoesters with a,P-unsaturated ketones.

New sulfur-containing spirocyclic scaffords were synthesized by two different enantioselective organocatalytic cascade reactions (13EJ07979). In the first synthesis, benzothiophene-2-one and an enal react in the presence of a secondary amine catalyst via a Michael-Aldol sequence to yield spiro-cyclo-hexenecarbaldehydes with excellent selectivities [20 1 diastereomeric ratios (dr) up to 20 1]. In the second reaction, the double Michael addition of ben-zothiophene-2-one to aromatic dieneones with primary amine catalysts yields the corresponding spiro-cyclohexanones with slighdy lower dr values. 

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