A Switchable Domino Process for the Construction of Novel CO₂‐Sourced Sulfur‐Containing Building Blocks and Polymers

Abstract

α‐Alkylidene cyclic carbonates (αCCs) recently emerged as attractive CO2‐sourced synthons for the construction of complex organic molecules. Herein, we report the transformation of αCCs into novel families of sulfur‐containing compounds by organocatalyzed chemoselective addition of thiols, following a domino process that is switched on/off depending on the desired product. The process is extremely fast and versatile in substrate scope, provides selectively linear thiocarbonates or elusive tetrasubstituted ethylene carbonates with high yields following a 100 % atom economy reaction, and valorizes CO2 as a renewable feedstock. It is also exploited to produce a large diversity of unprecedented functional polymers. It constitutes a robust platform for the design of new sulfur‐containing organic synthons and important families of polymers.

Exovinylene Cyclic Carbonates: Multifaceted CO2‐Based Building Blocks for Modern Chemistry and Polymer Science

“…The presence of the carbonyl and olefinic site in αCCs, both of which react with R‐SH reagents, makes it possible to form structurally divergent products using appropriate catalysts and/or operative conditions (Scheme 17). DBU promotes the fast thiolysis of αCCs, delivering oxo‐thiocarbonates (kinetic product) with high yields (89–99 %, 38 a – g ) in less than 1 min at rt [133] . The reversibility of the reaction is proven in concept by the dynamic exchange of the thiol fragments of two structurally different oxo‐thiocarbonates, producing four new scaffolds.…”

“…When DBU is replaced with 2,2‐dimethoxy‐2‐phenylacetophenone (DMPA) photocatalyst, i.e. a radical generator, the thiol addition onto the αCC occurs exclusively via the thiol–ene reaction, furnishing a trisubstituted ethylene carbonate with a thioether moiety ( 40 a ) at r.T. with high yield (95 %) [133] …”

“…DBU promotes the fast thiolysis of αCCs, delivering oxo-thiocarbonates (kinetic product) with high yields (89-99 %, 38 a-g) in less than 1 min at rt. [133] The reversibility of the reaction is proven in concept by the dynamic exchange of the thiol fragments of two structurally different oxo-thiocarbonates, producing four new scaffolds. After an extended reaction time, oxo-thiocarbonates are almost quantitatively transformed into elusive sulfur-containing tetrasubstituted ethylene carbonates (thermodynamic product) with a medium to high selectivity (43-100 %; 39 a-g).…”

“…[164,165] The polyaddition of bisαCC with thiols represents an alternative pathway for the fabrication of these sulfur polymers. [133] Using DBU catalyst (5 mol%) at r.T., novel poly(cyclic carbonate-co-thioether)s, with M n of 16 000 to 75 000 g mol À 1 , were obtained. By analogy to the thiolysis of αCCs (cf.…”

Direct Conversion from Carbon Dioxide to Luminescent Poly(β-alkoxyacrylate)s via Multicomponent Tandem Polymerization-Induced Emission

“…10 In many reported works, bis(cyclic carbonate)s (bis-CCs) were firstly prepared from CO 2 and diepoxides, then diamines were introduced to react with bis-CCs via non-regioselective ring opening reactions to obtain poly(hydroxyl urethane)s. [11][12][13] To solve the regioselectivity issue, Detrembleur et al synthesized bis(-alkylidene cyclic carbonate)s (bis-CCs) from CO 2 and bis(propargylic alcohol)s, which could further react with nucleophiles such as diamines, diols and dithiols via regioselective ring opening reactions to generate poly(urethane)s, poly(carbonate)s and poly(thiocarbonate)s, respectively (Scheme 1B). 14,15 Jian et al synthesized a highly reactive trivinyl methacrylate-type monomer from CO 2 and 1,3butadiene via a three-step procedure. Then the monomer was used for the copolymerization with ethylene toward a new class of ester-functionalized polyethylenes (Scheme 1C).…”