Ligand-enabled switch of the regioselectivity-determining step allowed for efficient regiocontrol in the aerobic oxidative Heck reaction of indole.

Pd-catalyzed reactions of azides with CO to access an isocynate intermediate have been developed extensively in recent years. However, the catalytic carbonylation of sensitive acyl azides has not been reported. Herein, we report a simple Pdcatalyzed carbonylation reaction of acyl azides with broad substrate scope, high efficiency, and simple operation under mild conditions, which provides facile access to acyl ureas. In addition, a mechanistic study was carried out by both experiment and DFT calculation. Control experiments and kinetic study revealed that the real active palladium species were Pd(0). The result of kinetic study suggested that palladium catalyst, azide, and CO were all involved in the turnover-limiting step except for amine. Further DFT study suggested that an unprecedented five-membered palladacycle intermediate was the key intermediate in the carbonylation reaction.

Amide is one of the most widespread functional groups in organic and bioorganic chemistry, and it would be valuable to achieve stereoselective C(sp 3 )À H functionalization in amide molecules. Palladium(II) catalysis has been prevalently used in the CÀ H activation chemistry in the past decades, however, due to the weakly-coordinating feature of simple amides, it is challenging to achieve their direct C(sp 3 )À H functionalization with enantiocontrol by Pd II catalysis. Our group has developed sulfoxide-2-hydroxypridine (SOHP) ligands, which exhibited remarkable activity in Pd-catalyzed C(sp 2 )À H activation. In this work, we demonstrate that chiral SOHP ligands served as an ideal solution to enantioselective C(sp 3 )À H activation in simple amides. Herein, we report an efficient asymmetric Pd II /SOHPcatalyzed β-C(sp 3 )À H arylation of aliphatic tertiary amides, in which the SOHP ligand plays a key role in the stereoselective CÀ H deprotonation-metalation step.

Amide is one of the most widespread functional groups in organic and bioorganic chemistry, and it would be valuable to achieve stereoselective C(sp3)−H functionalization in amide molecules. Palladium(II) catalysis has been prevalently used in the C−H activation chemistry in the past decades, however, due to the weakly‐coordinating feature of simple amides, it is challenging to achieve their direct C(sp3)−H functionalization with enantiocontrol by PdII catalysis. Our group has developed sulfoxide‐2‐hydroxypridine (SOHP) ligands, which exhibited remarkable activity in Pd‐catalyzed C(sp2)−H activation. In this work, we demonstrate that chiral SOHP ligands served as an ideal solution to enantioselective C(sp3)−H activation in simple amides. Herein, we report an efficient asymmetric PdII/SOHP‐catalyzed β‐C(sp3)−H arylation of aliphatic tertiary amides, in which the SOHP ligand plays a key role in the stereoselective C−H deprotonation‐metalation step.

When pepsin is incubated with benzyloxycarbonyl-~-glu-p~C]~-tyr ethyl ester, p*C] tyr ethyl ester remains bound to the enzyme, but when benzyloxycarbonylp*C]-~-glu-~-tyr ethyl ester is used as a substrate, no radioactivity remains associated with the protein.