Dmytro O. Tymoshenko

Synthesis of Heterocycles by Palladium-Catalyzed Intramolecular Heteroarylation

Abstract Synthesis of heterocycles by intramolecular C N bond formation through a palladium-catalyzed Hartwig–Buchwald reaction is described. The review covers the results reported for the synthesis of five- and six-membered rings, as well as medium-size and macro-heterocycles over the past 15 years. The review is organized by the size of the rings formed with further partition into subsections based on number of heteroatoms on the ring or fused ring systems. A separate section deals with tandem C C/C N palladium-catalyzed annulation sequences and cascades.

The Direct Carbamoylation of Organometallic Reagents with 1,2,3-Benzotriazole-1-carboxamides

Various (hetero)aromatic amides are synthesized efficiently by the carbamoylation of organometallic reagents.

Stereochemical aspects of novel 5,6-dihydro-4H-1,3-oxazines

Novel polysubstituted 5,6-dihydro-4H-1,3-oxazines are synthesized by 1,4-cycloaddition of unactivated olefins with N-acyliminiums from benzotriazole precursors. The configuration and conformation of the products are deduced from NMR investigation. The regio- and exo–endo stereochemistry of the cycloaddition are discussed. Conformations of compounds of six types of substitution (6-mono; 6,6-, 5,6- and 4,6-di; 4,6,6- and 4,5,6-tri) are rationalized on the basis of axial-1,3-repulsion and the anomeric effect.

Preparation and synthetic utility of 3-(benzotriazol-1-ylmethyl)areno- and -hetareno[b]thiophenes

3-(Functionalized-methyl)- and 3-alkenylareno(hetareno)[b]thiophenes 13–16 are prepared via the side chain elaboration of 3-(benzotriazol-1-ylmethyl)thiophenes 10d–f,h, readily available from the condensation of 1-benzotriazolyl-3-chloroacetone 7 with aromatic or heteroaromatic thiols followed by dehydrative cyclization of 1-(benzotriazol-1-yl)-3-[aryl(hetaryl)thio]acetones 9d–f,h.