Polar, functionalized diene-based material. III. Free-radical polymerization of 2-[(N,N-dialkylamino)methyl]-1,3-butadienes

Access to Highly Stereodefined 1,4-cis-Polydienes by a [Ni/Mg] Orthogonal Tandem Catalytic Polymerization

A [Ni/Mg]-catalyzed orthogonal tandem polymerization has been developed starting from enol phosphates. Initial investigations conducted on branched 1,3-dienes as monomers enabled identification of a Mg-initiated polymerization process leading to 1,4-cis-polydienes. When aryl enol phosphates are used as monomers, the [Ni/Mg]-catalyzed tandem polymerization affords 1,4-cis-polydienes with selectivities up to 99%. Elastomeric or crystalline materials were obtained by simple structural modifications of the monomeric unit. This tandem approach appears as a straightforward and efficient way to enforce diversity and selectivity in diene polymerization while retaining a fair degree of control, just as observed for stepwise systems that are accessible through established time- and manpower-consuming synthetic procedures.

The Synthesis of Ipsenol and Ipsdienol: A Review (1968-2020)

Herein I present a review on the synthesis of ipsenol and ipsdienol, two aggregation pheromones of bark beetles, isolated from different species of genus Ips, and serious pests of conifer forests. I have covered the literature for around fifty years, since 1968 to 2020. This account has been divided in different sections and sub-sections, including a general and brief outlook on their isolation, structure and biological activity, to continue with the reported synthesis of racemic ipsenol and ipsdienol, including my own contribution to topic, and the presentation of reports describing the synthesis of enantiomerically pure ipsenol and ipsdienol. Particular attention has been devoted to identify and highlight racemic or enantiomerically pure "isoprene synthons", and isoprenylation methods employed in the synthesis of ipsenol and ipsdienol, of general interest for related terpene derivatives synthesis.

Reversible addition–fragmentation chain transfer polymerization of myrcene derivatives: an efficient access to fully bio-sourced functional elastomers with recyclable, shape memory and self-healing properties

The rubber industry has been faced with critical challenges including unsustainable fossil-based monomer sources, lack of functionality and growing environmental concerns of waste vulcanizates.

Highly selective cis-1,4 copolymerization of dienes with polar 2-(3-methylidenepent-4-en-1-yl) pyridine: an approach for recyclable elastomers

We report the coordination copolymerization of a new polar diene-based monomer (MPEP), with isoprene or butadiene. After being quaternized, the resultant materials exhibit remarkable thermal reshaping and recycling properties.

Synthesis of 1,3-Butadiene and Its 2-Substituted Monomers for Synthetic Rubbers

Synthetic rubbers fabricated from 1,3-butadiene (BD) and its substituted monomers have been extensively used in tires, toughened plastics, and many other products owing to the easy polymerization/copolymerization of these monomers and the high stability of the resulting material in manufacturing operations and large-scale productions. The need for synthetic rubbers with increased environmental friendliness or endurance in harsh environments has motivated remarkable progress in the synthesis of BD and its substituted monomers in recent years. We review these developments with an emphasis on the reactive routes, the products, and the synthetic strategies with a scaling potential. We present reagents that are primarily from bio-derivatives, including ethanol, C4 alcohols, unsaturated alcohols, and tetrahydrofuran; the major products of BD and isoprene; and the by-products, activities, and selectivity of the reaction. Different catalyst systems are also compared. Further, substituted monomers with rigid, polar, or sterically repulsive groups, the purpose of which is to enhance thermal, mechanical, and interface properties, are also exhaustively reviewed. The synthetic strategies using BD and its substituted monomers have great potential to satisfy the increasing demand for better-performing synthetic rubbers at the laboratory scale; the laboratory-scale results are promising, but a big gap still exists between current progress and large scalability.

AIBN-Promoted Synthesis of Bibenzo[ b][1,4]thiazines by the Condensation of 2,2'-Dithiodianiline with Methyl Aryl Ketones

A series of bibenzo[ b][1,4]thiazines with various functional groups has been synthesized by a free-radical condensation reaction. Bibenzo[ b][1,4]thiazines were obtained in moderate to good yield (up to 85%) through a one-step reaction of readily available 2,2'-dithiodianiline and methyl aryl ketones with AIBN as radical initiator in HOAc. Bibenzo[ b][1,4]thiazines exhibit diversiform solid-state packing.

Highly cis-1,4-selective coordination polymerization of polar 2-(4-methoxyphenyl)-1,3-butadiene and copolymerization with isoprene using a β-diketiminato yttrium bis(alkyl) complex

A novel polar monomer 2-MOPB has been (co)polymerized to afford the highly cis-1,4 regulated P(2-MOPB) and P(2-MOPB-co-IP) of new plastics and rubber depending on the compositions.

Allylboration as a versatile tool for the in situ post-polymerization functionalization of 1,4-cis-poly(butadiene)

Allylboration is a versatile and robust tool for the one-pot, catalyst free post-polymerization functionalization of novel borylated 1,4-cis-poly(butadiene) from insertion copolymerization.

Synthetic method for the preparation of 2-aminomethyl-1,3-diene derivatives through indium-mediated 1,3-butadien-2-ylation of imines

An efficient method for the preparation of a variety of 2-aminomethyl-1,3-dienes was developed through the reaction of imines with organoindium reagent generated in situ from indium and 1,3-dibromo-2-butyne. Three-component reactions of aldehydes, amines, and organoindium reagents gave successful results in a one-pot process.