Trends in lipase-catalyzed asymmetric access to enantiomerically pure/enriched compounds

Over the last few years, there has been a dramatic increase in the number of publications in the field of lipase-catalyzed reactions performed in common organic solvents, ionic liquids or even non-conventional solvents. A fairly large percentage of these publications have emerged from organic chemists who have recognized the potential of biocatalysis as a viable and popular technique in organic synthesis. Considerable research has shown that reactions catalyzed by enzymes are more selective and efficiently performed than many of their analogues in the organic chemistry laboratory. This review article focuses on some of the recent developments in the rapidly growing field of lipase-catalyzed asymmetric access to enantiomerically pure/enriched compounds. The literature search is dated back to the last five years and covers some comprehensive examples.     

Steroids as chiral model compounds for selective reactions with metals

Our own work on steroid compounds with defined conformation as chiral model compounds for investigations of chemo-, regio- and stereoselectivity of metal-mediated new reactions is reviewed. Reactions with nickelacycles, (π-allyl)zirconoxycarbene complexes, iron tricarbonyl complexes of dienes and 1-azadienes, the Ru-catalyzed synthesis of 1,3-dihydropyrrol-2-ones from 1-azadienes, the Pd-catalyzed cyclopropanation of 1-azadienes, syntheses with cuprio steroids, copper complexes of amino alcohol derivatives and the copper-mediated hydroxylation of nonactivated C-H bonds with molecular oxygen are discussed.