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.