An efficient and simple synthesis of novel and densely substituted N-benzyl-1H-pyrroles 6a-r is described by a 1,4-addition/isomerization/ring closure/demetalation cascade process of alkynyl Fischer carbene complexes 1a-f and 2a and α-imino glycine methyl esters 3a, b, d, g, h, and k promoted with LDA.

The combination of cinchona-alkaloid-derived primary amine and Au(I) -phosphine catalysts allowed the selective C-H functionalization of two adjacent carbon atoms of pyrroles under mild reaction conditions. This sequential dual activation provides seven-membered-ring-annulated pyrrole derivatives in excellent yields and enantioselectivities.

Polysubstituted pyrroles were regioselectively synthesized in moderate to good yields via the copper acetate-catalyzed [3 + 2] annulation reaction of readily accessible aziridines and nitroalkenes. This reaction was proposed to proceed through a key azomethine ylide intermediate generated by selective C-C bond cleavage of the aziridine followed by annulation with nitroalkenes under aerobic cond...

Ir-catalyzed C-H borylation is found to be compatible with Boc protecting groups. Thus, pyrroles, indoles, and azaindoles can be selectively functionalized at C-H positions beta to N. The Boc group can be removed on thermolysis or left intact during subsequent transformations.

The polarity reversible nature of azomethine imines as the crucial transformation enables the tandem Michael addition/imine isomerization/[3+2] cycloaddition to proceed under mild, transition-metal-free conditions to form cyclohepta[b]pyrroles in a single operation starting from readily available acyclic precursors with a broad substrate scope.

Titanium-catalyzed hydroamination of 1,4- and 1,5-diynes by primary amines leads to imino-alkynes that undergo in situ 5-endo dig and 5-exo dig cyclization reactions, respectively. The products are 1,2,5-trisubsituted pyrroles accessed directly from readily available diyne starting materials.

Arylsulfinyl groups direct the metal-free, regiospecific, nucleophilic ortho-allylation of pyrroles and pyrazoles. Mechanistic studies support the intermediacy of allylsulfonium salts that undergo facile thio-Claisen rearrangement onto the heterocyclic ring, giving products of coupling. The strategy has been adapted to allow regiospecific propargylation of the heterocyclic substrates.

A novel strategy has been identified for the regioselective synthesis of 3,4-disubstituted quinolines and 2,3,5-trisubstituted pyrroles from simple alkenes via anti-Markovnikov selectivity under palladium catalysis. The salient features are synthesis of two different heterocycles, readily available starting materials, broad substrate scope, moderate to good yields and use of molecular oxygen as...

Polysubstituted pyrroles were efficiently synthesized in moderate yields by a one-pot multicomponent reaction starting from primary amines, ethyl glyoxalate and 2-bromoacetophenones in the presence of pyridine in refluxing acetonitrile. This methodology was utilized to synthesize a highly substituted benz[g]indole.