No abstract

The Morita-Baylis-Hillman (MBH) reaction affords highly functionalised allylic alcohols containing a new stereogenic centre. These MBH adducts are very versatile and have been transformed into a large range of products, some of which have medicinal potential. Several examples of asymmetric syntheses of MBH adducts have been reported, although a generally applicable method remains to be developed. Biocatalytic approaches for the synthesis and enzymatic kinetic resolution of MBH adducts have been reported, and are discussed in detail in this review. Enzymes able to catalyse the asymmetric MBH reaction have been identified, but selectivity and efficiency have generally been low. Lipases, esterases and nitrile-converting enzymes have all been successfully applied in the resolution of MBH adducts, with excellent selectivity being realised in most cases.

The capacity of the nitrogen nucleophile, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to reduce aryl-and heteroaryl disulfides to the corresponding mercaptans is demonstrated. While dicarboxylated disulfide analogues afford the mono-DBU disulfide salts, as confirmed by X-ray crystallography, the corresponding methyl esters are cleaved normally.

No abstract

No abstract