ChemInform Abstract: Metal‐Catalyzed Oxidations of C—H to C—N Bonds

Abstract

Metal-Catalyzed Oxidations of C-H to C-N Bonds

Evidence for a One‐Electron Mechanistic Regime in Dirhodium‐Catalyzed Intermolecular CH Amination

“…[2] In initial work focusing on intramolecular amination reactions that yield cyclic amine products, kinetic data were found to be consistent with a mechanism in which the ratelimiting step is the formation of an iminoiodinane, PhI= NSO 3 R, from sulfamate ester and hypervalent iodine oxidant PhIA C H T U N G T R E N N U N G (OAc) 2 (Equilibrium (I) in Scheme 1). Importantly, radical clock experiments provided no evidence for the involvement of radicals in these intramolecular reactions.…”

“…[1,2] Although several transition metals have been shown to accomplish oxidative CÀH amination, [3][4][5][6][7][8][9][10][11][12] metal-metal bonded dirhodium complexes are the best catalysts for this process in terms of their efficiency and selectivity, and are therefore utilized in a number of synthetic applications. [13,14] Despite the successful application of dirhodium-catalyzed CÀH aminations, a major drawback is that very little is known about the mechanism of the reaction.…”

“…This complex is actually a Rh 2 II,III bis-axial chloro adduct, [Rh 2 A C H T U N G T R E N N U N G (esp) 2 Cl 2 ]…”

Iron-mediated intermolecular N-group transfer chemistry with olefinic substrates

“…Equimolar mixtures of styrene or toluene and a para-substituted styrene or toluene derivative, respectively, were treated with 1-azidoadamantane in the presence of a stoichiometric amount of the Fe complex 1. The ratios of the resulting aziridines and benzylamines were determined by GC/MS analysis and by 1 H NMR integration of the spectra taken on unpuried material. The results are summarized in Table 1.…”

Total Synthesis of Biologically Active Natural Products Based on Highly Selective Synthetic Methodologies

“…We then postulated that this intermediate could be accessed from 59 via rhodium-catalyzed benzylic and allylic C-H amination reactions, followed by an intramolecular nucleophilic attack of a nitrogen atom on a sulfamate group, based on Du Bois' protocol. 76,77) Since, to our knowledge, such an approach to heterocyclic compounds had not been reported previously, we became interested in probing the scope and limitation of this particular pyrrolidine synthesis. 78) We prepared a panel of various substitution patterns of cyclic sulfamates 61 from alcohols 60 by sulfamation, rhodium-catalyzed C-H amination, and butoxycarbonylation and explored the feasibility of their cyclizations.…”