Boron-Catalyzed C1 Copolymerization of Arsonium and Sulfoxonium Ylides toward Unrepresented Structures and Fluorescence Properties.

The first synthesis of well-defined poly(methylene-co-1,1-diphenylpropenenylene) (C1-co-C1'), equivalent to poly(ethylene-co-diphenylbutadiene) copolymer was accomplished by C1 copolymerization of novel diphenylpropenyl triphenyl arsonium ylides (Ph2AY) and dimethylsulfoxonium methylide (Me2SY) using B-thexylborepane as an initiator. All polymerization conditions, including feed ratio, temperature, and reaction time, were optimized. A series of photoluminescent poly(ethylene-co-diphenylbutadiene) were synthesized at different feed ratios, opening a new synthetic horizon for poly(ethylene-co-disubstitutedbutadiene). Notably, a new C1 segment, resulting from a double bond rearrangement, was confirmed by  NMR, resulting in an unprecedented two-monomer three-structure random terpolymer. An unexpected red-shift phenomenon in the fluorescence spectra was observed with an increase in the ratio of Ph2AY in the copolymer. This shift is attributed to the aggregation of diphenylbutadiene segment, akin to through-space conjugation (TSC), likely induced by a decrease in the crystallinity of copolymers. Furthermore, another disubstituted allylic triphenyl arsonium ylides, (E)-2-phenylbutenyl triphenyl arsonium ylide (MePhAY) was also synthesized and investigated. These additional compounds expand knowledge and potential applications of such copolymerization techniques in advanced materials.

Catalytic asymmetric assembly of octahydroindolones: divergent synthesis of lycorine-type amaryllidaceae alkaloids (+)-α-lycorane and (+)-lycorine.

We report the first catalytic asymmetric approach to octahydroindolones and a divergent enantioselective synthesis of perhydroindole alkaloids, as exemplified by lycorine-type Amaryllidaceae alkaloids (+)-α-lycorane and (+)-lycorine, from a common intermediate by using a highly concise route. The assembly of octahydroindolones employs a catalytic enantioselective 1,4-conjugate addition of nitro dienynes, followed by a TsOH-catalyzed cascade synthesis of highly functionalized enones, and a diastereoselective intramolecular Michael addition.

Catalytic asymmetric synthesis of 1,3-enyne scaffolds: design and synthesis of conjugated nitro dienynes as novel Michael acceptors and development of a new synthetic methodology.

A novel catalytic enantioselective synthesis of functionalized 1,3-enynes has been developed featuring the design and synthesis of conjugated nitro dienynes as a useful new class of Michael acceptors. Moreover, a simple, yet flexible catalytic cascade approach to functionalized enantioenriched acyclic α,ß-enones and cyclic dienones has also been developed.