Ming-Bo Zhou

Copper-Catalyzed Intramolecular C−H Oxidation/Acylation of Formyl-N-arylformamides Leading to Indoline-2,3-diones

A new, efficient Cu-catalyzed intramolecular C-H oxidation/acylation method has been developed for the synthesis of substituted indoline-2,3-diones (isatins). In the presence of CuCl(2) and O(2), a variety of formyl-N-arylformamides underwent the tandem reaction to afford the corresponding indoline-2,3-diones in moderate to good yields. It is noteworthy that the reaction serves as the first example of transition-metal-catalyzed transformation for the preparation of indoline-2,3-diones.

Metal-free oxidative tandem coupling of activated alkenes with carbonyl C(sp2)–H bonds and aryl C(sp2)–H bonds using TBHP

A metal-free oxidative tandem coupling of activated alkenes with carbonyl C(sp2)–H bonds and aryl C(sp2)–H bonds using TBHP is established for the synthesis of 3-(2-oxoethyl)indolin-2-ones. This method allows 1,2-difunctionalization of the C–C double bond in N-arylacrylamides by simultaneous formation of two C(sp2)–C(sp3) bonds.

Oxidative 1,2-difunctionalization of activated alkenes with benzylic C(sp3)–H bonds and aryl C(sp2)–H bonds

DTBP (di-tert-butyl peroxide) is utilized to mediate oxidative 1,2-difunctionalization of activated alkenes with an aryl C(sp(2))-H bond and a benzylic C(sp(3))-H bond for the synthesis of functionalized oxindoles. This reaction is a new organomediated strategy for alkene difunctionalization facilitated by Lewis acids.

Rhodium(III)‐Catalyzed [3+2]/[5+2] Annulation of 4‐Aryl 1,2,3‐Triazoles with Internal Alkynes through Dual C(sp2)H Functionalization

A rhodium(III)-catalyzed [3+2]/[5+2] annulation of 4-aryl 1-tosyl-1,2,3-triazoles with internal alkynes is presented. This transformation provides straightforward access to indeno[1,7-cd]azepine architectures through a sequence involving the formation of a rhodium(III) azavinyl carbene, dual C(sp(2))-H functionalization, and [3+2]/[5+2] annulation.

Palladium-catalyzed oxidative difunctionalization of alkenes with α-carbonyl alkyl bromides initiated through a Heck-type insertion: a route to indolin-2-ones.

The oxidative interception of various σ-alkyl palladium(II) intermediates with additional reagents for the difunctionalization of alkenes is an important research area. A new palladium-catalyzed oxidative difunctionalization reaction of alkenes with α-carbonyl alkyl bromides is described, in which the σ-alkyl palladium(II) intermediate is generated through a Heck insertion and trapped using an aryl C(sp(2))-H bond. This method can be applied to various α-carbonyl alkyl bromides, including primary, secondary, and tertiary α-bromoalkyl esters, ketones, and amides.

Hexafluoroantimonic acid catalysis: formal [3+2+2] cycloaddition of aziridines with two alkynes.

A practical method for the synthesis of azepine derivatives, a typical seven-membered heterocyclic ring system, was developed and involves the use of hexafluoroantimonic acid to catalyze a formal [3+2+2] cycloaddition of aziridines with two alkynes. This method was applicable to two of the same or different terminal alkynes for the [3+2+2] cycloaddition with unactivated aziridines, and furnished the corresponding azepine derivatives in good yields with good levels of chemo- and regioselectivity. The mechanism was also discussed according to the results of the in situ HRMS and (1)H NMR analysis.

Alkylation of terminal alkynes with transient σ-alkylpalladium(II) complexes: a carboalkynylation route to alkyl-substituted alkynes.

A mild and general alkylation of terminal alkynes with transient σ-alkylpalladium(II) complexes for assembling alkyl-substituted alkynes is described. This method represents a new way to the use of transient σ-alkylpalladium(II) complexes in organic synthesis through 1,2-carboalkynylation of alkenes.