Copper (I) Catalyzed Sp 3 C-H Arylation of N -Arylglycine Ester Derivatives under Aerobic Conditions

Decyanative Heteroarylations of Glycine Derivatives

Amino acids and aromatic nitrogen heterocycles are widely used in pharmaceuticals. Herein, we present an effective visible-light-driven thiobenzoic acid (TBA)-catalyzed decyanative C(sp3)-H heteroarylation of glycine derivatives. This process occurs under mild and straightforward conditions, affording a range of valuable yet challenging-to-obtain α-heteroaryl amino acid derivatives. Moreover, this organocatalytic C(sp3)-C(sp2) bond formation reaction is applicable to the late-stage modification of various short peptides.

Eosin-Y/Cu(OAc)2-catalyzed aerobic oxidative coupling reactions of glycine esters in the dark

Catalytic aerobic oxidative coupling reactions of glycine esters with β-keto acids, indoles, naphthols, and pyrrole have been realized at ambient temperature via the manipulation of the ground state reactivity of eosin-Y in the presence of Cu(OAc)₂ in the dark. This method delivers structurally diverse unnatural amino acid derivatives under mild reaction conditions. UV-vis absorption spectroscopy, cyclic voltammetry, X-ray photoelectron spectroscopy, high-resolution mass spectrometry, and control experiments were performed to formulate a plausible mechanistic pathway. The step economy, broad substrate scope, use of air as a green oxidant, and operationally simple set-up make this protocol highly appealing for both academic and industrial applications.

Cyanation of glycine derivatives

We report a catalytic oxidative C-H cyanation of glycine derivatives using a simple copper(i) catalyst with NFSI as an oxidant via a radical process to furnish α-cyano glycine derivatives, which are useful intermediates for organic synthesis. CuCl acted as both a one-electron reductant and a transition-metal catalyst in this transformation. NFSI served as a one-electron oxidant and generated a N-centered radical as a H-abstractor. The reaction displayed broad substrate scope and mild reaction conditions.

TfOH-Catalyzed N-H Insertion of α-Substituted-α-Diazoesters with Anilines Provides Access to Unnatural α-Amino Esters

A time-economical TfOH-catalyzed N-H insertion between anilines and α-alkyl and α-aryl-α-diazoacetates provides a straightforward approach to access unnatural α-amino esters, which readily undergo various transformations and can thus be used for the synthesis of pharmaceutically relevant molecules. The α-amino esters were obtained in moderate to excellent yields.

Thiocyanation of α-amino carbonyl compounds for the synthesis of aromatic thiocyanates

A procedure for K2S2O8-mediated thiocyanation of α-amino carbonyl compounds has been developed for the synthesis of aromatic thiocyanates. A series of α-amino carbonyl compounds have been investigated, and the desired products are obtained in 74%–93% yields. This strategy has the advantages of simple reaction conditions without use of a transition-metal catalyst, high regioselectivity, and high efficiency. Moreover, we found that arylamine thiocyanates can also be obtained from α-amino carbonyl compounds and potassium thiocyanate in the presence of CoCl2·6H2O, I2, and dimethyl sulfoxide through the cleavage of the C–N bond. To explore the reaction mechanism, we designed several control experiments and proposed a possible mechanism using the experimental results and related literature reports.

K2S2O8-HFIP synergistically promoted para-selective sp3 C-H bond diarylation of glycine esters

A metal-free K₂S₂O₈-HFIP synergistically promoted double Friedel-Crafts alkylation between a glycine derivative and N-substituted aniline was developed to efficiently synthesize diarylmethane derivatives with high para-selectivity. The reaction proceeded smoothly in the absence of any metal and ligand, and exhibited a good tolerance of functional groups.

Cu(i)-Catalyzed amidation/imidation of N-arylglycine ester derivatives via C–N coupling under mild conditions

A copper-catalyzed cross-dehydrogenative amidation/imidation of N-arylglycine ester derivatives with benzamides, aromatic heterocyclic amides (oxindole, isatins), acyclic and cyclic amides (lactams) and imides (phthalimide, succinimide) under aerobic conditions has been developed.

Revisiting 1-chloro-1,2-benziodoxol-3-one: efficient ortho-chlorination of aryls under aqueous conditions

The ortho-selective amide directing group assisted chlorination of aryls with the easily accessible 1-chloro-1,2-benziodoxol-3-one as oxidant as well as chlorinating reagent is reported in the absence of a radical initiator. The open air, aqueous conditions and recyclable reagent demonstrate the green principles involved in the reaction.

Auto-oxidation promoted sp3 C–H arylation of glycine derivatives

An auto-oxidation promoted sp³ C–H arylation reaction between N-aryl glycine derivatives and electron-rich arenes, leading to the formation of N-aryl α-aryl α-amino acid derivatives, is described. This atom-economical and environmentally benign reaction proceeds smoothly under mild reaction conditions and requires only Brønsted acid and oxygen (balloon). A plausible radical involved mechanism is proposed.

Iron(iii)-catalyzed chelation assisted remote C–H bond oxygenation of 8-amidoquinolines

We have developed a simple, efficient oxygenation of C–H bonds that are geometrically inaccessible in 8-amidoquinolines with inexpensive and nontoxic iron(iii) catalyst. The chelation assisted remote benzoxylation protocol tolerates a wide substrate scope and is operationally simple.