Carbonylative Suzuki–Miyaura couplings of sterically hindered aryl halides: synthesis of 2-aroylbenzoate derivatives
作者:Aya Ismael、Troels Skrydstrup、Annette Bayer
DOI:10.1039/d0ob00044b
日期:——
diversely substituted 2-aroylbenzoate esters featuring a new protocol for the carbonylative coupling of aryl bromides with boronic acids and a new strategy to favour carbonylative over non-carbonylative reactions. Two different synthetic pathways - (i) the alkoxycarbonylation of 2-bromo benzophenones and (ii) the carbonylative Suzuki-Miyaura coupling of 2-bromobenzoate esters - were evaluated. The latter approach
The constituents of Californian redwood: the constitution, absolute stereochemistry, and chemistry of sequirin-B and sequirin-C
作者:N. A. R. Hatam、D. A. Whiting
DOI:10.1039/j39690001921
日期:——
Two new natural phenols have been isolated from Sequoia sempervirens heartwood. By spectroscopic and chemical methods, one, sequirin-B, is shown to be (2R,4S,5S)-4-(3,4-dihydroxyphenyl)-5-hydroxy-2-(4-hydroxy-phenyl)tetrahydropyran (I; R = H). The second, sequirin-C, was isolated as its methyl ether; it is shown to be (2S,3S)-(E)-3-(3,4-dimethoxyphenyl)-5-(4-methoxyphenyl)pent-4-ene-1,2-diol (V).
从红杉心材中分离了两种新的天然酚。通过光谱和化学方法,显示一种为Sequirin-B,为(2 R,4 S,5 S)-4-(3,4-二羟基苯基)-5-羟基-2-(4-羟基苯基)四氢吡喃(I; R = H)。分离出第二种,Sequirin-C,作为其甲基醚。显示为(2 S,3 S)-(E)-3-(3,4-二甲氧基苯基)-5-(4-甲氧基苯基)戊-4-烯-1,2-二醇(V)。