Palladium-Catalyzed Oxidative C–N Bond Coupling Involving a Solvent-Controlled Regioselective Bromination Process

Abstract

Stereoselective palladium-catalyzed oxidative C-N bond coupling reactions between aromatic amines and alkenes involving a solvent-controlled regioselective bromination process under 1 atm of oxygen atmosphere are disclosed, providing easy access to two different brominated enamines. The addition of hydrogen peroxide (30% aq) as a co-oxidant in the system is crucial for the dehydrogenative aminohalogenation under molecular oxygen (1 atm), and in such a case, the C-N bond coupling/electrophilic bromination reaction cascade is proposed. Furthermore, the different reaction media leads to a switched regioselectivity of the process.

Direct Trifluoromethylthiolation and Perfluoroalkylthiolation of C(sp2)H Bonds with CF3SO2Na and RfSO2Na

“…Under the same reaction conditions for indoles, the reaction of pyrroles afforded 5 a – c in good yields. Enamines, an important building block for a variety of biologically and synthetically interested nitrogen‐containing heterocycles,23 were also used for the synthesis of 6 a – b .…”

Direct Trifluoromethylthiolation and Perfluoroalkylthiolation of C(sp2)H Bonds with CF3SO2Na and RfSO2Na

“…[22] We were able to do direct trifluoromethylthiolation reaction of pyrroles (Scheme 1). Under the same reaction conditions for indoles,t he reaction of pyrroles afforded 5a-c in good yields.Enamines,animportant building block for avariety of biologically and synthetically interested nitrogen-containing heterocycles, [23] were also used for the synthesis of 6a-b.…”

Palladium/Copper‐Cocatalyzed Oxidative Amidobrominations of Alkenes

“…Resubmitting 4 b to the standard reaction conditions led to the formation of 3 d in 47 % yield. This transformation could be an electrophilic process in which the bromination of (enamide‐type) N ‐vinylated sulfoximine 4 was initiated by a copper/dioxygen‐catalyzed bromide‐to‐bromonium oxidation 1b. However, for achieving a high yield in the formation of 4 , the presence of the palladium complex was essential as demonstrated by control experiments (with 4 a as substrate).…”