Silver-catalysed direct amination of unactivated C–H bonds of functionalized molecules

Abstract

Carbon-nitrogen bond formation from inert C-H bonds is an ideal organic transformation and a highly desirable method for the synthesis of N-containing molecules due to its high efficiency and atom economy. In this report, we develop a general reaction to achieve an unprecedented selective intramolecular amination of unactivated C-H bond in the absence of complex directing groups. Functionalized heterocyclic products are built up from readily available linear amines through simple and reliable silver catalysis, representing a new silver-based C-H functionalization. This method displays preference for primary sp 3 C-H bonds and exhibits distinct chemo-and regioselectivity compared to existing methods of direct amination (Hofmann-Löffler-Freytag reaction and nitrene insertion). The study highlights the manipulation of unfunctionalized groups in organic molecules to furnish complex structural units in the natural and bioactive molecules.

Expeditious diastereoselective synthesis of elaborated ketones via remote Csp3–H functionalization

“…An intramolecular KIE of 1.7 was measured in the reaction of 2-methyl-3-phenylpropanoic-3- d acid ( 8 - d 1 ) with methyl 4-(1-azidovinyl)benzoate under the standard reaction conditions (equation 4). Both sets of KIE experiments are consistent with a reaction mechanism in which C–H bond cleavage is rate-limiting4950.…”

Controllable cyanation of carbon-hydrogen bonds by zeolite crystals over manganese oxide catalyst

“…In these cases, much success has been achieved by employing primary alcohols, aldehydes and aldoximes as precursors for the formation of C-N bonds1101112. In contrast, the ammoxidation of more easily available hydrocarbon is challenging, because of the high stability of sp 3 -hybridized C-H bonds14151617181920. In the past few years, homogeneous copper and palladium catalysts have been regarded to be active for C-N formation from C-H bonds to form amides and carbazoles as major products21222324, although these homogeneous catalysts are difficult to separate and regenerate from the reaction system.…”

Efficient synthesis of 2-arylquinazolines via copper-catalyzed dual oxidative benzylic CH aminations of methylarenes

“…In these syntheses, the key step is to construct C-N bonds of the cyclization. Recently, transition-metal-catalyzed oxidative aminations of sp 3 C-H bond have emerged as important methods for C-N bond formations because of short steps and atom-economical advantages [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38]. In particular, copper as an inexpensive and lowly toxic metal catalyst, has been employed to catalyze the formation of C-N bond via a sp 3 C-H amination [39][40][41][42][43][44][45][46][47][48][49].…”