A Rh-catalyzed intermolecular coupling of diazomalonates with arene C-H bonds is reported. The reaction is initiated by electrophilic C-H activation, which is followed by coupling of the arylrhodium(III) complex with the diazomalonate. In most cases, arenes with oximes, carboxylic acids, and amines as directing groups cross-couple with diazomalonates with excellent regioselectivities and functional group tolerance, and thus, this reaction offers a new route to α-aryl carbonyl compounds for specific applications.

A directing group-free approach for C2-selective carbenoid functionalization of NH-indoles is presented. Using [RuCl(2)(p-cymene)](2) as catalyst and alpha-aryldiazoesters as carbenoid source, 2-alkylated indoles were obtained in up to 96% isolated yield. Similarly, a regioselective carbenoid functionalization of NH-pyrroles was also achieved.

A Rh(III)-catalyzed oxidative [4 + 1] cycloaddition of benzohydroxamic acids and α-diazoesters is achieved to afford benzolactams in up to 93% yields. With the N-OAc amido moiety as a directing group, the ortho-C-H is selectively functionalized and the catalytic reaction exhibits excellent tolerance to different functional substituents. A notable rhodacyclic complex is isolated and structurally characterized, suggesting that C-H/N-H cyclometallation is a key step in the catalytic cycle.

A Pd(II)-catalyzed oxidative direct C(sp(2))-H/C(sp(3))-H cross coupling of anilides with α-dicarbonyl compounds with Mn(OAc)3·2H2O as the oxidant is reported and this protocol provides facile access to α-aryl malonates and β-keto esters in good yields and regioselectivity.