2,5-Bis{[(–)-(S)-1-(4-methylphenyl)ethyl]iminomethyl}thiophene

Abstract

The title chiral bis-aldimine, C24H26N2S, was synthesized using a solvent-free Schiff condensation. The mol­ecule displays crystallographic C 2 symmetry, with the S atom lying on the twofold axis parallel to [100]. As a consequence of the (S,S) stereochemistry, the tolyl groups are oriented towards opposite faces of the thiophene core, giving a twisted conformation for the whole mol­ecule. Mol­ecules are arranged in the crystal in a herringbone-like pattern, without any significant inter­molecular contacts.

Crystal structures of four chiral imine-substituted thiophene derivatives

“…The azomethine bond, which is isoelectronic with the vinyl bond and possesses similar optoelectronic and thermal properties, is easily accessible through the Schiff condensation under near ambient reaction conditions (Morgan et al, 1987;Pé rez Guarìn et al, 2007;Sicard et al, 2013). ISSN 2056-9890 We report here the synthesis and X-ray characterization of such thiophene derivatives, as a continuation of a partially published record (Bernè s et al, 2013;Mendoza et al, 2014). We are improving a general solvent-free approach for these syntheses, recognising that ecological aspects in organic chemistry have become a priority, in order to minimize the quantity of toxic waste and by-products, and to decrease the amount of solvent in the reaction media or during work-up (Tanaka & Toda, 2000;Noyori, 2005).…”