In this letter, an unprecedented cross-coupling reaction between copper carbene and nitroso radical has been developed. This radical-carbene coupling reaction (RCC reaction) offers a novel approach for the preparation of various isoxazolines, which features the construction of C-C, C-O, and C═N bonds in a one-pot process. The synthetic utility of our method is further enhanced by its mild reaction conditions, wide substrate scope, and simple procedures.

Herein, we present a novel [3 + 2] cycloaddition reaction of β-keto esters with nitrile oxides, which were generated in situ from copper carbene and tert-butyl nitrite. This three-component reaction provides new methodology for the direct synthesis of fully substituted isoxazole derivatives, featuring mild reaction conditions, readily accessible starting materials and simple operation. The experimental studies and DFT calculations suggest that the reaction starts with the generation of the key intermediate nitrile oxides, followed by a [3 + 2] cycloaddition reaction of β-keto esters to give the final isoxazole products.

Through the interception of amide ylides with sulfonamides, we herein report the first general example of an intermolecular condensation reaction between sulfonamides and amides. Beyond formamides, this approach was successfully applied to a variety of lactams and linear amides, giving rise to a broad array of (E)-N-sulfonyl amidines.

An impressive and new [3 + 3]-cycloaddition of α-diazocarbonyl compounds with N-tosylaziridines via synergetic catalysis of AgOTf and Cu­(OAc)2 has been well described, which offers efficient access to highly substituted 2H-1,4-oxazine derivatives. A variety of α-diazocarbonyl compounds and N-tosylaziridines were compatible substrates with convenient operations under mild reaction conditions.

A simple and efficient method has been developed for the preparation of primary oxamates and α-ketoamides through the oxidative coupling of diazo compounds and NH 4 I. Under the optimized reaction conditions, a range of diazoesters and αdiazoketones was explored, and the corresponding products were obtained in moderate to good yields. This protocol is metal-free, is performed under mild conditions, has a wide substrate scope, and offers operational simplicity.

The alkyne unit is a versatile building block in organic synthesis and the development of selective multifunctionalization of alkynes is an important object of research in this field. Herein, we report an interesting gold-catalyzed, four-component reaction that achieves the oxo-arylfluorination or oxo-arylalkenylation of internal aromatic or aliphatic alkynes, efficiently breaking a carbon-carbon triple bond and forming four new chemical bonds. The reaction divergence can be controlled by site-directing functional groups in the alkynes; the presence of a phosphonate unit favors the oxo-arylfluorination, while the carboxylate motif benefits oxo-arylalkenylation. This reaction is enabled by an Au(I)/Au(III) redox coupling process using Selectfluor as both an oxidant and a fluorinating reagent. A wide range of structurally diverse α,α-disubstituted ketones, and tri- or tetra-substituted unsaturated ketones have been prepared in synthetically valuable yields and with excellent chemo-, regio- and stereoselectivity. The gram-scale preparation and late-stage application of complex alkynes have further enhanced their synthetic value.