Metalloporphyrin Catalyzed C–H Amination

Abstract

Direct C−H bond functionalization to form C−N bonds via nitrenoid insertion is one of the most effective strategies to construct N-functionalized molecules of importance. In this context, metalloporphyrins have established themselves as effective catalytic systems for such transformation, following an outer-sphere pathway. In the past few years C(sp 3 )−H bond amination has progressed in leaps and bounds, tackling the chemo-/regioselectivity issue not only in small molecules but also in complex molecules through late-stage functionalization, furnishing valuable N-scaffolds. It is only very recently that the biocatalytic approach with metalloporphyrin-based enzymes has emerged as a promising research area demonstrating very good regio-and stereoselectivity toward the development of environmentally benign C−H amination processes. Importantly, the progress in aromatic C−H bond amination has also gained prominence lately under metalloporphyrin catalysis. This review covers development achieved to date in metalloporphyrin-catalyzed C−H amination, including the very nascent biocatalytic C−H bond nitrenoid insertion, in addition to providing an insight on the mechanistic aspects as well.

Ultra‐Deep Oxidative Desulfurization of Model Oil Catalyzed by In Situ Carbon‐Supported Vanadium Oxides Using Cumene Hydroperoxide as Oxidant

“…Therefore, the reactivity of DBT and 4,6-DMDBT in ODS is dominated by steric hindrance derived from methyl groups, which make the interaction difficult between the sulfur and the catalytic active site. [46] Therefore, the desulfurization ratio of 4,6-DMDBT is 92.5 %, which is lower than that of DBT.…”

RuV‐Acylimido Intermediate in [RuIV(Por)Cl2]‐Catalyzed C–N Bond Formation: Spectroscopic Characterization, Reactivity, and Catalytic Reactions

“…[Ru IV (TDCPP)Cl 2 ]/ 1 a can even catalyze C(sp 3 )–H amination of cyclooctane 9 i to give 10 ia , albeit in a 12 % yield (Figure S1). Amination of C(sp 3 )−H bonds via metalloporphyrin‐mediated nitrene transfer was previously confined to stoichiometric amination of indan by [Ru VI (Por)(N)(OH)]/(CF 3 CO) 2 O [33] and catalytic amination involving other types of proposed nitrenoids such as M(NSO 2 Ar) and M(NAr) species [1c,e,i,o] . The C(sp 3 )–H amination reactions by [Ru IV (Por)Cl 2 ]/N 3 COR (Por=TTP, TDCPP) to give N ‐acyl amines 10 in up to 96 % yield (Figure 7) demonstrate the catalytic activity of a metalloporphyrin for such acylnitrene transfer reactions.…”

Azides and Porphyrinoids: Synthetic Approaches and Applications. Part 1—Azides, Porphyrins and Corroles

“…On the other hand, organic azides revealed to be potentially green resources to transfer nitrenes, since the only by-product formed throughout the generation of nitrenes from azides is dinitrogen. Alkene aziridination and C-H amination are among the most common uses for nitrene transfer reactions, although several other very promising applications have been recently explored [95][96][97][98][99][100][101][102][103][104]. Those most recent developments employing porphyrin metal complexes as efficient catalysts are summarized below.…”