The reaction of terminal alkynes with imines using ReBr(CO)(5) as a catalyst results in the production of N-alkylideneallylamines and not the conventional propargylamines. The substituent on the imine nitrogen is important, and a diphenylmethyl group gave the best result. The catalytic cycle of this regioselective C-C bond forming reaction appears to involve the formation of an alkynyl rhenium species and subsequent nucleophilic attack of the alkynyl β-carbon atom on the imine carbon to give a vinylidene rhenium species.

The rhenium-catalyzed reaction of terminal alkynes with imines gives N-alkylideneallylamine derivatives. A diphenylmethyl group as the substituent on the imine nitrogen gave the best result. Deuterium labeling experiments revealed that the regioselective addition of both the hydrogen and the N-alkylideneaminoalkyl group to the terminal alkynes also proceeded stereoselectively. While alkynes bearing primary and secondary alkyl-, vinyl-, and aryl groups were applicable to the catalytic reaction, tertiary alkyl- and silyl-substituted alkynes gave propargylamines. The C–C bond-forming step via the nucleophilic attack of the alkynyl β-carbon on the imine carbon leading to the formation of a vinylidene rhenium species appears to be involved in the catalytic cycle.

The synthesis of self-doped conductive poly(3,4-ethylenedioxythiophene) (PEDOT) bearing phosphonic acid moieties is first reported. The UV-vis-NIR spectrum of the film clearly confirmed self-doping. The polymer exhibited good water solubility as a salt with NMe3, as demonstrated by filtration tests with a membrane filter (0.02 µm). This result is in contrast to a PEDOT/poly(4-styrene sulfonate) dispersion, which cannot pass through the filter. The conductivity of a drop-cast film reached 1.3 × 102 S cm−1. The thermogravimetric analysis and elementary analysis of the drop-cast film showed that the conductive polymer presents as a NMe3 salt, which might protect the materials from acid-induced corrosion. The developed conductive polymer has the potential for being applied in various organic electronic materials.

Rhenium-Catalyzed Regio-and Stereoselective Addition of Imines to Terminal Alkynes Leading to N-Alkylideneallylamines. -The use of ReBr(CO)5 as catalyst in the presented reaction forms no conventional propargylamines. The substituent an the imine nitrogen is important and a diphenylmethyl group gives the best results. The reactions of the compounds (IVc) and (IVd) give a complex mixture of unidentified products and the starting material, respectively. -(FUKUMOTO*, Y.; DAIJO, M.; CHATANI, N.; J. Am. Chem. Soc. 134 (2012) 21, 8762-8765, http://dx.