Direct enantioselective aldol reactions catalyzed by a proline-thiourea host-guest complex.

Proline-thiourea host-guest complex-catalyzed direct enantioselective aldol reactions have been developed, in which the catalytic activities were evaluated in the direct asymmetric aldol reactions of various aromatic aldehydes and cyclohexanone.

Catalytic intermolecular aldehyde-ketone coupling via acyl phosphonates.

The first catalytic intermolecular aldehyde-ketone coupling via acyl phosphonate is reported. Acyl phosphonates are potent acyl anion precursors, which generate acyl anion equivalents under the influence of cyanide anion via phosphonate-phosphate rearrangement. These anions readily react with activated ketones to form acyloin type coupling in 41-95% yields.

Cyanide ion promoted addition of acyl phosphonates to ethyl cyanoformate: synthesis of tertiary carbinols via tandem carbon-carbon bond formations.

New cyanation/phosphonate-phosphate rearrangement/C-acylation reactions of cyanophosphate anion with cyanoformate esters are described. Phase-transfer cocatalysts facilitate cyanide-catalyzed reactions between acyl phosphonates and cyanoformates to afford protected tertiary carbinol products in good to excellent yields (74-95%). Ethyl cyanoformate is used as a cyanide source and electrophile.

Role of copper species in the oxidative dimerization of arylboronic acids: synthesis of symmetrical biaryls.

Certain Cu(I) and Cu(II) salts are able to mediate the dimerization of arylboronic acids in DMF. They provide the corresponding symmetrical biaryls in moderate to very good yields. It is possible to run the reaction catalytically under an oxygen atmosphere without a significant loss of yields.

Generation of aryl radicals from arylboronic acids by manganese(III) acetate: synthesis of biaryls and heterobiaryls.

The efficient generation of aryl radicals from arylboronic acids by manganese(III) acetate is described. In aromatic solvents, in situ generated aryl radicals afford the corresponding biaryls in very good yields. This method works selectively, and yields are better than those from similar, previously described methods.