922-65-6Relevant articles and documents
Polymethylene-Based Eight-Shaped Cyclic Block Copolymers
Hadjichristidis, Nikos,Jiang, Yu
, (2020)
A new strategy was developed for the synthesis of well-defined eight-shaped polymethylene (PM, equivalent to polyethylene)-based cyclic block copolymers, [c-(PM-b-PCL)]2, according to the following four steps: (a) synthesis of a B-thexyl-boracyclic initiator by cyclic hydroboration of 1,4-pentadiene-3-yl 2,2,5-trimethyl-1,3-dioxane-5-carboxylate with thexylborane; (b) polyhomologation of dimethylsulfoxonium methylide using this boracyclic initiator to afford α,ω-dihydroxyl linear PM (PM-OH)2; (c) synthesis of 4-miktoarm star block copolymers, (PM-alkyne)2-(PCL-N3)2, by esterification, deprotection, and ring-opening polymerization (ROP); and (d) intramolecular cyclization of (PM-alkyne)2-(PCL-N3)2, under high-dilution condition by copper-catalyzed "click" chemistry. All intermediates and final products were characterized by high-temperature gel permeation chromatography, proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. Initial studies on the thermal and self-assembly behavior of the cyclic block copolymers and their corresponding precursors revealed a significant influence of the cyclic structure on the properties.
Total synthesis of (±)-kalihinol C
White, Ryan D.,Keaney, Gregg F.,Slown, Corin D.,Wood, John L.
, p. 1123 - 1126 (2004)
The total synthesis of kalihinol C, a bis-isonitrile marine diterpenoid isolated from Acanthella sp., is reported. The decalin framework was established via an intramolecular Diels-Alder cycloaddition and subsequently functionalized through a series of substrate-controlled diastereoselective transformations to install the tertiary isonitrile, β-hydroxy isonitrile, and pendant tetrahydrofuranyl ring.
Construction of Silicon-Containing Seven-Membered Rings by Catalytic [4 + 2 + 1] Cycloaddition through Rhodium Silylenoid
Sasaki, Ikuo,Ohmura, Toshimichi,Suginome, Michinori
supporting information, p. 2961 - 2966 (2020/04/10)
A rhodium-catalyzed [4 + 2 + 1] cycloaddition involving 1,3-diene, alkyne, and silylene to afford silicon-containing seven-membered rings was established. In the presence of a rhodium catalyst bearing bis(diphenylphosphino)methane (DPPM), nona-1,3-dien-8-yne derivatives reacted efficiently at 80-110 °C with boryl(isopropoxy)silane or boryl(diethyamino)silane, which reacts as the synthetic equivalent of silylene, to afford 1-silacyclohepta-2,5-dienes (2,5-dihydro-1H-silepines). Regiodivergent and chemo- and stereoselective functionalization of the seven-membered nonconjugated diene was achieved by hydroboration mediated by Cs2CO3 or an iridium catalyst.
F- Nucleophilic-Addition-Induced Allylic Alkylation
Tian, Panpan,Wang, Cheng-Qiang,Cai, Sai-Hu,Song, Shengjin,Ye, Lu,Feng, Chao,Loh, Teck-Peng
supporting information, p. 15869 - 15872 (2016/12/23)
Herein we present a novel strategy based on palladium-catalyzed allylic alkylation by taking advantage of the nucleophilic addition of external fluoride onto gem-difluoroalkenes as the initiation step. The merit of this protocol is highly appealing, as it enables a formal allylation of trifluoroethylarene derivatives through the in situ generation of β-trifluorocarbanions, which otherwise are deemed to be problematic in deprotonative allylation. Furthermore, this strategy distinguishes itself by high modularity, operational simplicity, and wide substrate scope with respect to allyl carbonates, giving rise to a broad array of homoallyltrifluoromethane derivatives, which otherwise would not be easily obtained using existing synthetic methods.
