Intermediates in the dehydrogenation of 3,3′,4,4′-tetrahydro-1,1′-binaphthyl. Some hydrogenated 1,1′-binaphthyls and benzo[j]fluoranthenes
作者:Malcolm Crawford、V. R. Supanekar
DOI:10.1039/j39680002328
日期:——
3,3′,4,4′-Tetrahydro-1,1′-binaphthyl can undergo dehydrogenation and cyclodehydrogenation simultaneously. Possible intermediates with various degrees of hydrogenation have been prepared and characterised. Some of these have been recognised as intermediates and thus the respective courses of the two parallel reactions have been traced.
A Mild Dihydrobenzooxaphosphole Oxazoline/Iridium Catalytic System for Asymmetric Hydrogenation of Unfunctionalized Dialins
作者:Bo Qu、Lalith P. Samankumara、Shengli Ma、Keith R. Fandrick、Jean-Nicolas Desrosiers、Sonia Rodriguez、Zhibin Li、Nizar Haddad、Zhengxu S. Han、Keith McKellop、Scott Pennino、Nelu Grinberg、Nina C. Gonnella、Jinhua J. Song、Chris H. Senanayake
DOI:10.1002/anie.201408929
日期:2014.12.22
Air‐stable P‐chiral dihydrobenzooxaphosphole oxazoline ligands were designed and synthesized. When they were used in the iridium‐catalyzed asymmetrichydrogenation of unfunctionalized 1‐aryl‐3,4‐dihydronaphthalenes under one atmosphere pressure of H2, up to 99:1 e.r. was obtained. High enantioselectivities were also observed in the reduction of the exocyclic imine derivatives of 1‐tetralones.
A visible light accelerated C–H functionalization reaction in palladium‐catalyzed arylation of vinyl arenes with diaryliodonium salts is reported in the absence of additional photosensitizer. The kinetic isotope effect (kH/kD) was changed from 3.6 (under darkness) to 1.1 when irradiated by visible light, which indicated that the C–H functionalization step was the rate determining step under darkness
据报道,在不使用其他光敏剂的情况下,可见光加速了CH-H在乙烯基芳烃与二芳基碘鎓盐的芳基化中的芳基化反应。在可见光照射下,动力学同位素效应(k H / k D)从3.6(在黑暗中)变为1.1,这表明C–H官能化步骤是黑暗中的速率决定步骤,并且通过C的照射而显着加速可见光。最后,通过该方案实现了具有高对映体特异性的邻四取代乙烯基芳烃阻转异构体的合成。
One-Pot Synthesis of Spirofuran and Benzocycloalka[1,2-<i>b</i>]furan Derivatives Using Manganese(III)-Mediated Oxidative Radical Cyclization
作者:Hiroshi Nishino、Reika Fujino
DOI:10.1055/s-2005-861807
日期:——
obtained by the oxidation of methylenebenzocycloalkanes with manganese(III) acetate in the presence of 1,3-dicarbonyl compounds. A similar oxidation of the benzocycloalkene derivatives produced the functionalized benzocycloalka[1,2-b]furans in good yields. However, l-benzyl-3,4-dihydronaphthalene gave both the corresponding spirofuran and benzocyclohexa[1,2-b]furan under the same oxidation conditions.
An Oxidation Induced by Potassium Metal. Studies on the Anionic Cyclodehydrogenation of 1,1′-Binaphthyl to Perylene
作者:Michel Rickhaus、Anthony P. Belanger、Hermann A. Wegner、Lawrence T. Scott
DOI:10.1021/jo101635z
日期:2010.11.5
Oxidative cyclization of 1,1′-binaphthyl (1) to perylene (2) can be achieved in essentially quantitative yield by the action of three or more equivalents of potassium metal in hot tetrahydrofuran. An overall reaction mechanism is proposed that accounts for all of the experimental observations reported by previous investigators and those from the present studies. The trans-6a,6b-dihydroperylene dianion (62−)