Oxidative oxy-cyclization of 2-alkynylbenzamide enabled by TBAB/Oxone: switchable synthesis of isocoumarin-1-imines and isobenzofuran-1-imine

A TBAB-controlled switchable synthesis of isocoumarin-1-imine and isobenzofuran-1-imine from 2-alkynylbenzamide in water is described in this paper.

Gold-catalyzed [4+3]- and [4+2]-annulations of 3-en-1-ynamides with isoxazoles via novel 6π-electrocyclizations of 3-azahepta trienyl cations

New gold-catalyzed [4+3]-annulations of 3-en-1-ynamides with isoxazoles afford 4H-azepines efficiently; this process involves 6π electrocyclizations of gold-stabilized 3-azaheptatrienyl cations. In the presence of Zn(OTf)2, the resulting 4H-azepines undergo skeletal rearrangement to furnish substituted pyridine derivatives. We subsequently develop new catalytic [4+2]-annulations between the same 3-en-1-ynamides and isoxazoles to deliver substituted pyridine products using Au(i)/Zn(ii) catalysts. This work reports the first success of the 6π electrocyclizations of heptatrienyl cations that are unprecedented in literature reports.

Regioselective 5-exo-dig oxy-cyclization of 2-alkynylbenzamide for the synthesis of isobenzofuran-1-imines and isobenzofuran

A TBAB-mediated regioselective radical cyclization of 2-alkynylbenzamide is described herein for the synthesis of isobenzofuran-1-imines. The reactions proceeded smoothly under mild conditions.

Synthesis of polycyclic sultams via a palladium-catalyzed reaction of 1-bromo-2-(cyclopropylidenemethyl)benzenes with 2-alkynylbenzenesulfonamides

Polycyclic sultams are efficiently synthesized through a palladium-catalyzed tandem reaction of 1-bromo-2-(cyclopropylidenemethyl)benzenes with 2-alkynylbenzenesulfonamides via double carbometallation.

A palladium-catalyzed tandem reaction of 2-alkynylbenzenesulfonamides with 2-(2-bromoarylidene)cyclobutanones

The core of benzo[f][1,2]thiazonin-5(4H)-one 3,3-dioxide is efficiently assembled through a palladium-catalyzed tandem reaction of 2-alkynylbenzenesulfonamides with 2-(2-bromobenzylidene)cyclobutanones via double carbometallation. A range of polycycles with a nine-membered sultam ring are generated in moderate to good yields.

A convenient palladium-catalyzed carbonylative synthesis of quinazolines from 2-aminobenzylamine and aryl bromides

An interesting approach for the synthesis of 2-functionalized quinazolines has been developed. Various quinazolines have been produced in moderate to excellent yields.

A facile route to 5-methyl-5H-indeno[1,2-c]quinolones via palladium-catalyzed cyclization of 2-alkynylbromobenzenes with N,N-dimethyl-2-alkynylanilines

A tandem reaction catalyzed by palladium is developed to provide a facile and simple route for the synthesis of 5-methyl-5H-indeno[1,2-c]quinolones.

Generation of 6H-benzo[f]cyclopenta[d][1,2]thiazepine 5,5-dioxides via a palladium-catalyzed reaction of 2-(2-alkynyl)benzenesulfonamide

An efficient approach for the assembly of 6H-benzo[f]cyclopenta[d][1,2]thiazepine 5,5-dioxides via a palladium-catalyzed tandem reaction of 2-(2-alkynyl)benzenesulfonamide with 2-alkynylvinyl bromide is reported. This transformation proceeds smoothly through a double carbopalladation with high efficiency.

An efficient route to tetrahydroindeno[2,1-b]pyrroles via a base-promoted reaction of (E)-2-alkynylphenylchalcone with 2-isocyanoacetate

A base-promoted cascade reaction of (E)-2-alkynylphenylchalcone with 2-isocyanoacetate provides a novel and efficient route for the synthesis of tetrahydroindeno[2,1-b]pyrroles. The reaction proceeds smoothly in air under mild conditions with high efficiency.