A convenient catalyst system for microwave accelerated cross-coupling of a range of aryl boronic acids with aryl chlorides.

A convenient microwave accelerated cross-coupling procedure between aryl chlorides with a range of boronic acids has been developed. An explanation for the low reactivity of highly fluorinated boronic acids in Suzuki coupling is provided.

Highly regioselective rhodium-catalysed hydroformylation of unsaturated esters: the first practical method for quaternary selective carbonylation.

Highly regioselective hydroformylation of unsaturated esters can be achieved when a highly reactive, ligand-modified, rhodium catalyst is employed near ambient temperatures (15-50 degrees C) and pressures over 30 bar. The use of 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phosphaadamantane shows distinct advantages over other commonly applied phosphanes in terms of reaction rate, and regio- and chemoselectivity. Hydroformylation of a range 1,1-di- and 1,1,2-trisubstituted unsaturated esters yields quaternary aldehydes that are forbidden products according to Keulemans Rule.

A versatile chemo-enzymatic route to enantiomerically pure beta-branched alpha-amino acids.

A series of diastereoisomers of beta-methyl-beta-phenylalanine analogues 1a-f have been prepared in enantiomerically pure form using a combination of chemo- and biocatalysis. Starting from l-threonine methyl ester 2, a range of beta,beta-disubstituted didehydroamino acids were obtained as their (Z)-isomers 6a-f. Asymmetric hydrogenation of these alkenes, using either the [Rh(R,R)-Et-DuPhos(COD)]BF4 or [Rh(S,S)-Et-DuPhos(COD)]BF4 catalyst, followed by hydrolysis yielded two of the four possible sets of diastereoisomers of the beta-branched amino acid.