Iron-catalyzed cross-coupling reactions between a bicyclic alkenyl triflate and Grignard reagents.

Fe-catalyzed cross-coupling reactions between a bicyclic alkenyl triflate and Grignard reagents were investigated. Under the optimized reaction conditions, various 2-substituted bicyclic alkenes were synthesized in moderate to excellent yields (52-93%). This method provided an efficient route for the synthesis of 2-substituted bicyclic alkenes with secondary alkyl groups which cannot be synthesized using previous methods such as Pd-catalyzed coupling reactions and lithium-halide exchange reactions.

Rhodium-catalyzed asymmetric cyclodimerization of oxabenzonorbornadienes and azabenzonorbornadienes: scope and limitations.

Cationic rhodium(I)-catalyzed cyclodimerization of oxabenzonorbornadienes produced naphtho[1,2-b]furan ring systems in a single step with excellent yields and excellent enantioselectivities. The effect of various Rh(I) catalysts, Ag(I) salts, solvents, and phosphine ligands on the yield and enantioselectivity of the reaction was investigated, and the scope and limitations of this reaction with various oxabicyclic alkenes were studied. Similar results were obtained with the azabenzonorbornadiene analogues, providing the corresponding cyclodimerization products in excellent yields and excellent enantioselectivities.

Stereoselective synthesis of Z alkenyl halides via Julia olefination.

Julia olefination between alpha-halomethyl sulfones and a variety of aldehydes afforded alkenyl halides in good to excellent yields with high E/Z stereoselectivities. Sulfones were readily prepared in two or three steps from commercially available reagents in good yields. Optimization revealed that the nature of the solvent, the base, and the additive were crucial to obtain the desired alkenyl halides.