From Tetrahydrofurans to Tetrahydrobenzo[ d]oxepines via a Regioselective Control of Alkyne Insertion in Rhodium-Catalyzed Arylative Cyclization.

The formation of chiral 5- and 7-membered tetrahydrofurans and tetrahydrobenzo[ d]oxepines is achieved via arylative cyclization of simple O-tethered alkyne-enoates in the presence of arylboronic acids and chiral dienes-rhodium catalyst under mild conditions. Access to such structures was achieved via a simple switch in the regioselectivity of the alkyne insertion thanks to a proper choice of the alkyne substituent.

Selective Methylation of Arenes: A Radical C-H Functionalization/Cross-Coupling Sequence.

A selective, nonchelation-assisted methylation of arenes has been developed. The overall transformation, which combines a C-H functionalization reaction with a nickel-catalyzed cross-coupling, offers rapid access to methylated arenes with high para selectivity. The reaction is amenable to late-stage methylation of small-molecule pharmaceuticals.

Chiral Bicyclo[2.2.2]octa-2,5-dienyltrifluoroborate Derivative as a Useful and Stable Precursor of C1-Symmetric Chiral Dienes.

A new approach has been developed to prepare monosubstituted C1-symmetric chiral dienes Ar-MSBod from easily accessible chiral bicyclo[2.2.2]octa-2,5-dienyltrifluoroborate derivative. This alkenyl trifluoroborate was synthesized in five steps from inexpensive (-)-carvone. This approach allows the construction of large libraries of diversely substituted chiral dienes via cross-coupling reactions with inexpensive and widely available aryl halides.

Access to Polyfunctionalized Chiral Piperidines through Enantioselective Addition-Carbocyclization Cascade Reaction Catalyzed by a Rhodium(I)-Diene Complex.

A new addition-carbocyclization cascade reaction initiated by arylboronic acids and catalyzed by a rhodium/chiral diene complex is described. Starting from N-bridged oxoenoate derivatives, highly functionalized piperidines bearing three contiguous stereogenic centers were obtained with excellent enantio- and diastereoselectivities.

Chiral pyrrolidines and piperidines from enantioselective rhodium-catalyzed cascade arylative cyclization.

A new rhodium-catalyzed asymmetric arylative cyclization of nitrogen-tethered alkyne-enoate with arylboronic acids is described. In this process two new carbon-carbon bonds and one stereocenter are formed, providing access to pyrrolidines and piperidines with good enantioselectivities by to the use of C1-symmetric chiral monosubstituted diene ligands.