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Nucleophilic addition of imidazolines to 1-halo-1-alkynes takes place by simple heating in DMF without any additives to give (Z)-N-(1-halo-1-alken-2-yl)imidazolines in good yield and in a highly regio- and stereoselective manner. These reaction conditions are also valid for the similar addition of imidazoles., (© 2011 American Chemical Society)

When a mixture containing 1‐halo‐1‐alkyne, a dinucleophilic agent, and a base (Cs2CO3 or K3PO4) was heated in DMF, regio‐ and stereo‐selective nucleophilic addition of the dinucleophilic agent to the acetylenes occurred. This reaction yielded (Z,Z)‐bis(haloalkene), which subsequently underwent Pd‐catalyzed cyclization through C−H bond activation, resulting in the formation of two‐oxygen‐ or ‐nitrogen‐containing hetero‐π‐conjugated compounds. N‐(5‐Hydroxynaphthalen‐1‐yl)methanesulfonamide was treated with 2‐phenyl‐1‐chloroethyne followed by 1‐chloro‐1‐hexadecyne. After these reactions, Pd‐catalyzed double C−H cyclization was employed to produce 1H‐2‐phenyl‐7‐tetradecylbenzofuro[7,6‐g]indole. Notably, this compound transformed into a fan‐shaped structure at 86 °C and transitioned into a smectic A phase characterized by a layered structure. [ABSTRACT FROM AUTHOR]

Examines enol ester as an olefinic partner in enyne cyclization. Preparation of a bicyclic carbon skeleton with stereodefined arrangement of functional groups; Proposal for the course of bicyclization; Titanium-medicated intramolecular cyclization of enol esters and acetylenes.

Analyzes the selective syntheses of metalated pyridines from two different unsymmetrical acetylenes. Variations of preparative methods of pyridines; Formulation of various syntheses of metalated pyridines; Distinction between the formation of titanated pyridines and conventional metal-catalyzed pyridine synthesis.

Abstract: When benzylamines having a chloroacetylene moiety were heated in wet toluene with a catalytic amount of rhodium trifluoroacetate dimer, intramolecular debenzylative cyclization took place to give butyrolactams. This method is a new entry to selective debenzylation of amines. [Copyright &y& Elsevier]

Coupling of acetylene, nitrile, and a titanium reagent, Ti(O-i-Pr)/2 i-PrMgCI, generated new azatitanacyclopentadienes in a highly regioselective manner. Their subsequent reaction with sulfonylacetylene afforded pyridyltitanium compounds, which, upon reaction with electrophiles, gave substituted pyridines virtually as a single isomer. When optically active nitriles were used in this reaction, chiral pyridines were obtained without loss of the enantiopurity. Alternatively, the azatitanacyclopentadiene prepared from an unsymmetrical acetylene reacted with an aldehyde or another nitrile to give furans or pyrroles having four different substituents again in a regioselective manner. [ABSTRACT FROM AUTHOR]

The article describes the preparation of unsaturated heterocyclic compounds with two heteroatoms. Heterocyclic compounds are used as synthetic intermediates found in natural and artificial products. The study discusses the process of copper-catalyzed double amination of haloacetylenes. An overview of the study is provided.

Examines the formation of benzyltitanium compounds via the metalative Reppe reaction of acetylene and a titanium reagent. Molecular structure; Selective cyclotrimerization of unsymmetrical acetylene to a single aromatic compound; First synthesis of alcyopterosin A.