Iron and copper complexes cooperatively catalyzed the arylmagnesiation of unfunctionalized alkynes including dialkylacetylenes, where the presence of both iron and copper catalysts is essential for high yields of 2-aryl-1-alkenylmagnesium bromides.

[reaction: see text] The first catalytic asymmetric synthesis of 2-aryl-2,3-dihydro-4-quinolones has been developed by way of a rhodium-catalyzed 1,4-addition of arylzinc reagents to 4-quinolones. These 1,4-adducts can be obtained with high enantioselectivity by the use of (R)-binap as a ligand, and high yields are realized by conducting the reactions in the presence of chlorotrimethylsilane.

[reaction: see text] A rhodium-catalyzed multicomponent-coupling reaction has been developed that involves a cross-coupling with organohalides as part of the reaction sequence. Through several experiments toward mechanistic investigations, it has also been demonstrated that the reaction most likely proceeds via a carborhodation-oxidative addition-reductive elimination pathway, which clearly contrasts to the corresponding palladium-catalyzed processes.

Addition of arylmagnesium bromides to aryl(alkyl)acetylenes proceeded in the presence of an iron catalyst and a N-heterocyclic carbene ligand to give high yields of the corresponding alkenylmagnesium reagents, which were transformed into tetrasubstituted alkenes by subsequent treatment with electrophiles. [reaction: see text]

Process research and development for a synthesis of the chiral carboxylic acid ( R )-2 as a key intermediate of the glucokinase activator ( R )-1 is described. The construction of the stereocenter at the α-carbon is a key point for the synthesis of ( R )-2. The proposed process utilizes desymmetrization of a ketene in situ generated from the corresponding racemic carboxylic acid Rac -2 with (R)-pantolactone as a chiral auxiliary followed by hydrolysis of the resulting ester. This key step has been successfully scaled up to 20 kg, which demonstrates that this synthetic approach is comparable with a previously reported approach via enantioselective hydrogenation.