10.1021/acs.joc.7b03205
The research focuses on the electrophile-dependent alkylation reactions of lithiated 4-alkoxyalk-4-enenitriles. The purpose of this study was to investigate the diastereoselective alkylation and acylation of acyclic nitriles, which are challenging due to the need to constrain rotatable single bonds and the inherent bonding of metalated nitriles. The researchers found that alkylation reactions with primary alkyl halides, sulfur, chlorine, and acyl cyanide electrophiles were highly selective, installing contiguous tertiary-quaternary stereocenters with high diastereoselectivity. In contrast, acylations with ester and carbonate electrophiles were modestly selective.
10.1002/pola.23836
The study investigates the synthesis and gas permeation properties of poly(diarylacetylene)s with substituted biphenyl and anthryl groups. Diarylacetylene monomers containing substituted biphenyl (1a–f) and anthryl (1g) groups were synthesized and polymerized using a TaCl5-n-Bu4Sn catalyst to produce the corresponding polymers (2a–g). The polymers exhibited high thermal stability, with onset temperatures of weight loss over 400°C in air. Free-standing membranes were prepared from several polymers, and desilylation of the Si-containing membrane 2c was carried out to afford 3c. The polymer membranes, particularly those with twisted biphenyl groups, showed high gas permeability, with oxygen permeability (PO2) values ranging from 130 to 1400 barrers. The study highlights the potential of these polymers for gas separation applications, with polymer 2d, containing chlorine atoms in the biphenyl group, demonstrating the highest gas permeability among the tested polymers.