to representative classes of carbon electrophiles (i.e., vinyl sulfones, nitroolefins, formaldehyde) is documented. We demonstrate that by using selected chiral tertiary amine/squaramide catalysts, the reactions of β,γ‐unsaturated cycloalkanones proceed through the dienolate Cα almost exclusively and provide all‐carbon quaternary cyclic ketone adducts in good yields with very high enantioselectivities
Variant G74C of arylmalonatedecarboxylase (AMDase) from Bordatella bronchoseptica has a unique racemising activity towards profens. By protein engineering, variant G74C/V43A with a 20‐fold shift towards promiscuous racemisation was obtained, based on a reduced activity in the decarboxylation reaction and a two‐fold increase in the racemisation activity. The mutant showed an extended substrate range
Nucleophilic addition to vinylketene- and vinylketenimine (allenylideneamine)tricarbonyliron(0) complexes
作者:Lawrence Hill、Christopher J. Richards、Susan E. Thomas
DOI:10.1039/c39900001085
日期:——
Nucleophiles add to C-1 of (vinylketene)tricarbonyliron(0) complexes to give β,γ-unsaturated carbonyl derivatives, whereas nucleophilic attack on a (vinylketenimine)tricarbonyliron(0) analogue occurs at C-2 and leads, after an oxidative work-up, to β,γ-unsaturated amides containing an a quaternary centre.