Recent advances in Pd-catalyzed oxidative couplings in the synthesis/functionalization of cyclic scaffolds using molecular oxygen as the sole oxidant

Over the past years, Pd(II)-catalyzed oxidative couplings enabled the achievement of molecular scaffolds with high structural diversity via C−C, C-N and C-O bond-formation reactions. In contrast to the use of stoichiometric amounts of more common oxidants, such as metal salts (Cu and Ag) and benzoquinone derivatives, the use of molecular oxygen in the direct or indirect regeneration of Pd(II) species presents itself as a more viable alternative in terms of economy and sustainability. In this review, we describe recent advances on the development Pd-catalyzed oxidative cyclizations/functionalizations, where molecular oxygen plays a pivotal role as the sole stoichiometric oxidant. 1 Introduction 2 Oxidative C-C and C-Nu Coupling 2.1 Intramolecular Oxidative C-Nu Heterocyclization Reactions 2.1.1 C-H Activation 2.1.2 Wacker/aza-Wacker Type Cyclization 2.1.3 Tandem Wacker/aza-Wacker and Cyclization/Cross Coupling Reactions 2.2 Intermolecular Oxidative C-Nu Heterocoupling Reactions 2.3 Intramolecular Oxidative (C-C) Carbocyclization Reactions 2.4 Intermolecular Oxidative C-C Coupling Reactions 2.4.1 Cyclization Reactions 2.4.2 Cross-Coupling Reactions 2.4.3 Homo-Coupling Reactions 3 Aerobic Dehydrogenative Coupling/Functionalization 4 Oxidative C-H Functionalization 5 Summary

Palladium(II)-Catalyzed Aerobic Oxidative O-H/C-H Isocyanide Insertion: Facile Access to Pyrrolo[2,1-c][1,4]benzoxazine Derivatives

Palladium-catalyzed aerobic oxidative cyclizations of substituted 2-(1H-pyrrol-1-yl)phenols with isocyanides via O-H/C-H insertion cascade have been developed. This strategy provides a facile access to pyrrolo[2,1-c][1,4]benzoxazine derivatives in good to excellent yields...

Recent Advances in Palladium-Catalyzed Oxidative Cyclizations

Heterocycles are very common substructures in a number of pharmaceuticals. Over the past several years, the use of palladium-catalyzed oxidative cyclization for heterocyclic synthesis has become much more prevalent. This review collects recent reports using palladium catalysis to synthesize a wide variety of heterocyclic scaffolds. Many of these reactions use oxygen as the terminal oxidant. Some salient mechanistic features are discussed.