A novel oxidative coupling of aldehydes to form C3-substituted phthalides facilitated by co-operative dual catalysis of a Rh(III) complex and an aryl amine is reported. The reaction involves a cascade ortho C-H activation-insertion-annulation sequence. This methodology is efficient and applicable for the homo- and heterocoupling of various functionalized aldehydes generating the corresponding phthalides in moderate to high yields.

Oxidative coupling of arenes by dual C−H activation, thereby avoiding prefunctionalization of coupling partners, is the ideal way to synthesize biaryls. This letter reports a palladium-catalyzed regioselective oxidative arylation of furan-2-carbonyl compounds with simple arenes to 5-arylfuran-2-carbonyls.The key for the high regioselectivity is the use of F + oxidants. The reaction is proposed to proceed through a Pd(II)−Pd(IV) catalytic cycle, wherein the substrates are activated by an electrophilic palladation mechanism, supported by preliminary mechanistic evidence.

A simple catalyst system consisting of Pd(OAc)2 and 3‐nitropyridine for the aerobic oxidative Heck coupling of cyclic enones, in particular challenging unsubstituted cyclic enones, with simple arenes by CH activation was investigated. This novel method was applied to various functionalized arenes and cyclic enones and allowed the synthesis of β‐aryl cyclic enones in modest to high yields.

The proposed reaction mechanism includes an initial ortho C-H activation followed by insertion and a final annulation step. -(TAN, P. W.; JUWAINI, N. A. B.; SEAYAD*, J.; Org. Lett. 15 (2013) 20, 5166-5169, http://dx.doi.org/10.1021/ol402145m ; Inst. Chem. Eng. Sci., Singapore 138665, Singapore; Eng.) -U. Scheffler 11-118

H Activation. -The simple catalyst system allows the coupling of cyclic enones with arenes using molecular oxygen as the oxidant. Only for fluoroarenes Ag 2CO3 is found to be more efficient than oxygen. -(CHUNG, L. G. Y.; JUWAINI, N. A. B.; SEAYAD*, J.; ChemCatChem 7 (2015) 8, 1270-1274, http://dx.doi.org/10.1002/cctc.201500079 ; Inst. Chem. Eng. Sci., Singapore 138665, Singapore; Eng.) -Mais 35-107