One-Pot Synthesis of Terminal Alkynes from Alkenes

The direct synthesis of terminal alkynes from widely available terminal alkenes is an unmet challenge in organic synthesis. Here, we show that alkyl and aromatic terminal alkenes can be converted to the corresponding alkynes in a one-pot process consisting of a Ru-catalyzed dehydrogenative hydrosilylation, followed by an oxidative dehydrogenative reaction of the vinyl silane intermediate, enabled by the combination of PhIO with BF3. This formal alkene dehydrogenation reaction with commercially available reagents and under mild reaction conditions gives access to terminal alkynes in a simple manner, including acetylene.

Continuous Flow Synthesis of Functional Isocyanate-Free Poly(oxazolidone)s by Step-Growth Polymerization

Flow chemistry presents many advantages over batch processes for the fast and continuous production of polymers under more robust, safer, and easily scalable conditions. Although largely exploited for chain-growth polymerizations, it has rarely been applied to step-growth polymerizations (SGP) due to their inherent limitations. Here, we report the facile and fast preparation of an emerging class of nonisocyanate polyurethanes, i.e., CO2-based poly(oxazolidone)s, by SGP in continuous flow reactors. Importantly, we also demonstrate that functional poly(oxazolidone)s are easily prepared by telescoping a flow module where SGP occurs with reagents able to simultaneously promote two polymer derivatizations in a second module, i.e., dehydration followed by cationic thiol-ene to yield poly(N,S-acetal oxazolidone)s. The functional polymer is produced at a high rate and functionalization degree, without requiring the isolation of any intermediates. This work demonstrates the enormous potential of flow technology for the facile and fast continuous production of functional polymers by SGP.

Graphene-aramid nanocomposite fibres via superacid co-processing

The development of graphene-polymer nanocomposite materials has been hindered by issues such as poor colloidal stability of graphene in liquid media, weak interactions between graphene and the host polymers as well as the lack of scalable and economical graphene synthesis routes. Chlorosulfonic acid (CSA) can spontaneously disperse graphene without the need for mechanical agitation, chemical functionalisation or surfactant stabilisation,1 however is incompatible with most polymers and organic materials. Here, we demonstrate how poly(p-phenylene terephthalamide) (PPTA) - the polymer which constitutes Kevlar - can be co-processed with graphene in CSA and wet-spun into nanocomposite fibres with minimal aggregation of graphene.

Mechanochemical synthesis of two-dimensional aromatic polyamides

2D aromatic polyamides (2DAPAs) were synthesized for the first time via a facile mechanochemical route under solvent-free and room temperature conditions.