Hypoiodite-catalysed oxidative homocoupling of arenols and tandem oxidation/cross-coupling of hydroquinones with arenes
作者:Muhammet Uyanik、Dai Nagata、Kazuaki Ishihara
DOI:10.1039/d1cc05171g
日期:——
We report the hypoiodite-catalyzed oxidative C–C homocoupling of arenols to biarenols or biquinones using aqueous hydrogen peroxide as an oxidant. In addition, by combining hypoiodite catalysis and lipophilic Lewis acid-assisted Brønsted acid catalysis under aqueous conditions, we achieved a tandem oxidation/cross-coupling reaction of hydroquinones with electron-rich arenes. These results highlight
作者:Gerhard Bringmann、Roland Götz、Paul A. Keller、Rainer Walter、Michael R. Boyd、Fengrui Lang、Alberto Garcia、John J. Walsh、Imanol Tellitu、K. Vijaya Bhaskar、T. Ross Kelly
DOI:10.1021/jo971495m
日期:1998.2.1
A convergent total synthesis of the anti-HIV michellamines (1) is described. The tetraaryl skeleton of the michellamines mas constructed by formation first of the inner (nonstereogenic) biaryl axis and subsequently of the two other (stereogenic) axes in a highly convergent manner. The key transformation features a double Suzuki-type cross-coupling reaction between binaphthalene ditriflate 26 and isoquinolineboronic acid 35. Ditriflate 26 is synthesized in six steps starting from diene 6 and 2,6-dibromobenzoquinone (9) in 21% overall yield. For large scale production of 26, a substantially shortened version of an existing procedure for the preparation of bisnaphthoquinone 13 was also developed, which allows far the preparation of 13 from benzoquinone and diene 6 in five steps and 67% overall yield. Binaphthoquinone 13 was subsequently converted into ditriflate 26 in three steps and 67% overall yield, By the described synthetic strategy, michellamines A (1a) and B (1b) are produced (1a:1b = 1:2.5) in 24.6% overall yield from diene 6. Curiously, none of the nonnaturally occurring atropoisomer 1c is formed.
Structural analogues of the michellamine anti-HIV agents. Importance of the tetrahydroisoquinoline rings for biological activity
作者:Heping Zhang、David E Zembower、Zhidong Chen
DOI:10.1016/s0960-894x(97)10057-9
日期:1997.10
A series of michellamine structural analogues was prepared in which the tetrahydroisoquinoline rings were substituted with a variety of simple aromatic ring systems. Additionally, the methyl groups on the central bis-naphthalene cores were replaced with hydrogen and methoxy. All the analogues were devoid of anti-HIV activity, suggesting that the heterocyclic portion of the tetrahydroisoquinoline ring is crucial for biological activity. (C) 1997 Elsevier Science Ltd.
Laatsch, Hartmut, Liebigs Annalen der Chemie, 1980, # 8, p. 1321 - 1347