Synthesis of cross-conjugated trienes by rhodium-catalyzed dimerization of monosubstituted allenes.

A rhodium(I)/dppe catalyst promoted dimerization of monosubstituted allenes in a stereoselective manner to give cross-conjugated trienes, which are different from those obtained by a palladium catalyst.

Synthesis of 3,3-disubstituted oxindoles by palladium-catalyzed tandem reaction of 2-(alkynyl)aryl isocyanates with benzylic alcohols.

A palladium complex sequentially promoted two mechanistically distinct reactions, the first, cyclization of 2-(alkynyl)aryl isocyanates with benzylic alcohols, and the second, [1,3] rearrangement of a benzyl group from oxygen to carbon, furnishing 3,3-disubstituted oxindoles in one pot.

Stereoselective oxindole synthesis by palladium-catalyzed cyclization reaction of 2-(alkynyl)aryl isocyanates with amides.

A new cyclization reaction occurred on treatment of 2-(alkynyl)aryl isocyanates with amides in the presence of a palladium(0)/diphosphine catalyst to stereoselectively form 3-(amidoalkylidene)oxindoles. A carbon-nitrogen bond as well as a carbon-carbon bond were simultaneously introduced onto the alkyne moiety to construct an oxindole skeleton with stereoselective placement of the amino substituent cis to the carbonyl group.

Stereoselective synthesis of 3-alkylideneoxindoles by palladium-catalyzed cyclization reaction of 2-(alkynyl)aryl isocyanates with organoboron reagents.

A palladium(0)/monophosphine catalyst promotes a cyclization reaction of 2-(alkynyl)aryl isocyanates with organoboron reagents to produce stereodefined 3-alkylideneoxindoles. The alkynyl and isocyanato groups undergo oxidative cyclization with Pd(0) to form an oxapalladacycle intermediate. Subsequent transmetalation and reductive elimination afford the product.

Efficient synthetic routes to aromatic compounds using ring-closing olefin metathesis followed by dehydration, oxidation, and tautomerization.

A simple synthetic approach to aromatic compounds using combinations of RCM, dehydration, oxidation, and tautomerization is described.