Wajid Ali

Copper-Catalyzed Esterification of Alkylbenzenes with Cyclic Ethers and Cycloalkanes via C(sp3)–H Activation Following Cross-Dehydrogenative Coupling

A copper-catalyzed cross-dehydrogenative coupling strategy has been developed for the synthesis of two classes of esters from simple solvents. The reaction of methylarenes with cyclic ethers resulted in α-acyloxy ethers involving four sp(3) C-H cleavages, while treatment of methylarenes with cycloalkanes led to the formation of allyl esters at the expense of six consecutive sp(3) C-H bonds.

Regiospecific Benzoylation of Electron-Deficient N-Heterocycles with Methylbenzenes via a Minisci-Type Reaction

A regioselective cross-dehydrogenative coupling between electron-deficient N-heterocycles (isoquinoline, quinolines, and quinoxalines) and methylbenzenes leading to regiospecific C-aroylation has been accomplished using AlCl3 as the catalyst in the presence of oxidant TBHP. This protocol is a practical alternative to the classical Minisci reaction.

Palladium-Catalyzed Synthesis of 2-Aryl-2H-Benzotriazoles from Azoarenes and TMSN3.

Substrate-directed ortho C-H amination of azoarenes using TMSN3 as the source of nitrogen leading to the synthesis of 2-aryl-2H-benzotriazoles has been accomplished with the help of Pd/TBHP combinations. An intermolecular o-azidation (C-N bond formation) followed by an intramolecular N-N bond formation via nucleophilic attack of one of the azo nitrogen onto the o-azide nitrogen leads to cyclization with the expulsion of N2.

Benzylic ethers as arylcarboxy surrogates in substrate directed ortho C–H functionalisation catalysed by copper

A copper catalysed ortho-benzoxylation of 2-arylpyridines has been accomplished using benzylic ethers as the alternative arylcarboxy sources (ArCOO–) via sp2 C–H bond activation. The use of the Pd/TBHP catalytic system is reported to install an o-aroyl (ArCO–) moiety at the 2-arylpyridine while the Cu/TBHP combination fixes a benzoxy (ArCOO–) group at the ortho site.

Organocatalytic Regioselective Concomitant Thiocyanation and Acylation of Oxiranes Using Aroyl Isothiocyanates

A regioselective and concomitant transfer of thiocyanate (-SCN) and aroyl/acyl (-COR) groups from aroyl/acyl isothiocyanates onto oxiranes was achieved, giving thiocyanato benzoates in 100% atom economy. In this biomimetic organocatalytic process, one part (-SCN) of aroyl/acyl isothiocyanates acts as the nucleophile whereas the other half (-COR) serves as an electrophilic partner.

Microwave-Assisted Cascade Strategy for the Synthesis of Indolo[2,3-b]quinolines from 2-(Phenylethynyl)anilines and Aryl Isothiocynates

The in situ generated o-alkynylthioureas obtain by reacting 2-(phenylethynyl)anilines and aryl isothiocynates undergo efficient cascade cyclization in the presence of Ag2CO3 to form indoloquinolines under microwave heating. The present tandem process allows the generation of a variety of indolo[2,3-b]quinolines derivatives in good to moderate yields with a wide functional group tolerance.

Benzyl bromides as aroyl surrogates in substrate directed Pd catalysed o-aroylation

An oxidative cross-coupling between directing substrates and benzyl bromides via the combined effect of oxidants TBHP and NMO, catalysed by Pd(II) has been investigated. Benzyl bromides served as efficient aroyl surrogates in this substrate directed C–H functionalisation. The in situ generated benzaldehyde originating from benzyl bromide is the active aroylating source.

Transition metal-free synthesis of α-ketoamides from arylmethyl ketones and alkylphosphoramides

A transition metal-free protocol has been developed for the synthesis of α-ketoamides from aryl methyl ketones and alkylphosphoramides in the presence of oxidant, aqueous tert-butyl hydroperoxide (TBHP). A series of aryl methyl ketones having both electron-donating as well as electron-withdrawing groups were successfully employed for the synthesis of their corresponding α-ketoamides using hexamethylphosphoramide and other alkylphosphoramides.

CCDC 983611: Experimental Crystal Structure Determination

Related Article: Wajid Ali, Srimanta Guin, Saroj Kumar Rout, Anupal Gogoi, Bhisma K. Patel|2014|Adv.Synth.Catal.|356|3099|doi:10.1002/adsc.201400360