Pt- and Au-catalyzed oxidative cyclization of 2-ethenyl-1-(prop-2′-yn-1′-ol)benzenes to naphthyl aldehydes and ketones: catalytic oxidation of metal-alkylidene intermediates using H2O and H2O2
Process for producing 1,3-naphthalenedicarboxylic acid
申请人:Ogawa Hiroshi
公开号:US20050187403A1
公开(公告)日:2005-08-25
1,3-Naphthalenedicarboxylic acid is produced by oxidizing 1,3-dialkylnaphthalene in a liquid-phase with an oxygen-containing gas in the presence of a C
2
-C
6
lower aliphatic carboxylic acid solvent and a catalyst comprising a heavy metal and a bromine compound. By regulating the ratio of the total number of bromine atoms fed into a reaction system to the total number of 1,3-dialkylnaphthalene molecules fed into the reaction system within a specific range, 1,3-naphthalenedicarboxylic acid is efficiently produced with low costs. Using 1,3-dimethylnaphthalene, as the starting 1,3-dialkylnaphthalene, which is produced by isomerizing dimethylnaphthalenes in a liquid phase in the presence of a catalyst comprising hydrogen fluoride and boron trifluoride together with a C
5
-C
10
alicyclic saturated hydrocarbon having a five-membered or six-membered ring structure, a highly pure 1,3-naphthalenedicarboxylic acid is efficiently produced.
A 1,3-carbonyl shift in the platinum-catalyzed aromatization of 2-epoxy-1-(methoxyalk-2-ynyl)benzenes
作者:Rupsha Chaudhuri、Arindam Das、Hsin-Yi Liao、Rai-Shung Liu
DOI:10.1039/c002660c
日期:——
A platinum-catalyzed reaction involving new aromatization/1,3-carbonyl shift cascade of 2-epoxy-1-(methoxyalk-2-ynyl)benzenes is reported. This skeletalrearrangement is mechanistically significant because it involves a remarkable 1,3-carbonyl shift to complete the aromatization and to regenerate the catalyst.
A highly efficient and regioselective method for constructing functionalized conjugated enals via the Tf2O-mediated tandem reaction of enaminones with thiophenols has been described. Chain products with excellent stereoselectivity could be obtained through substrate regulation. Additionally, a feasible method for synthesizing β-naphthalaldehydes through PhSO2Na/DABCO promoting hydrogen atom transfer