Revisiting the Minisci Reaction: New Mild Amidoalkylation of Benzo-Fused N-Heteroaromatic Bases under Metal-Free Conditions

Direct Amino-α-C-H Heteroarylation of Amides under Electrochemical Conditions

An electrochemical hydrogen atom transfer (HAT) strategy for the direct amino-α-C-H heteroarylation of amides is described. The cheap TMSN3 acts as a hydrogen atom transfer reagent. A series of heteroarenes including quinoxalin-2(1H)-ones, 4-methylquinoline, isoquinoline, 2-methylquinoxaline, benzothiazole, etc., and various readily available amides/lactams were suitable. The reaction has the characteristics of a wide range of substrates, good regioselectivity, chemical oxidant-free conditions, etc.

Photoexcited sulfenylation of C(sp3)-H bonds in amides using thiosulfonates

A photoexcited sulfenylation of C(sp³)-H bonds in amides is developed for the synthesis of sulfenyl amides using thiosulfonates as a sulfur source. In the presence of easily available and inexpensive Na₂-eosin Y, TBHP and K₂CO₃, various sulfenyl amides can be obtained under the irradiation of blue light at room temperature.

A Journey from June 2018 to October 2021 with N,N-Dimethylformamide and N,N-Dimethylacetamide as Reactants

A rich array of reactions occur using N,N-dimethylformamide (DMF) or N,N-dimethylacetamide (DMAc) as reactants, these two amides being able to deliver their own H, C, N, and O atoms for the synthesis of a variety of compounds. This account highlights the literature published since June 2018, completing previous reviews by the author.

Copper-promoted direct amidation of isoindolinone scaffolds by sodium persulfate

Isoindolinones are ubiquitous structural motifs in natural products and pharmaceuticals. Establishing an efficient method for structural modification of isoindolinones could significantly facilitate new drug development. Herein, we describe copper-promoted direct amidation of isoindolinone scaffolds mediated by sodium persulfate. The method exhibits mild reaction conditions and high site-selectivity, and enables the structural modification of the drug indobufen ester with various amides with yields of 49 to 98%. It is also gram-scalable. Additionally, the reaction mechanism appears to involve a radical and a carbocationic pathway.

Hydrogen Atom Transfer-Driven Enantioselective Minisci Reaction of Amides

Minisci-type reactions constitute one of the most powerful methods for building up complexity around basic heteroarenes. The most desirable variants involve formal oxidative coupling of a C-H bond on each partner, leading back to the simplest possible starting materials. We herein disclose a method that enables such a coupling of linear amides and heteroarenes with full control of enantioselectivity at the newly formed stereocenter as well as site selectivity on both the heteroarene and the amide. This is achieved by the use of a chiral phosphoric acid catalyst in conjunction with diacetyl as a combined hydrogen atom transfer reagent and oxidant. Diacetyl is directly photoexcitable, and thus, no extraneous photocatalyst is required: an added feature that contributes to the simplicity and practicality of the protocol.