Biphilic Organophosphorus-Catalyzed Intramolecular C<sub>sp<sup>2</sup></sub>–H Amination: Evidence for a Nitrenoid in Catalytic Cadogan Cyclizations
作者:Trevor V. Nykaza、Antonio Ramirez、Tyler S. Harrison、Michael R. Luzung、Alexander T. Radosevich
DOI:10.1021/jacs.7b13803
日期:2018.2.28
equiv of phosphetane P-oxide 3·[O] and 2-nitrosobiphenyl. Experimental and computationalinvestigations into the C-N bond forming event suggest the involvement of an oxazaphosphirane (2 + 1) adduct between 3 and 2-nitrosobiphenyl, which evolves through loss of phosphetane P-oxide 3·[O] to give the observed carbazole product via C-H insertion in a nitrene-like fashion.
Abstract The coupling reaction of diverse arylhalogenids with phenyl-boronic acid undersolvent-freeconditions has been performed using a palladium catalyst. The order of reactivity was complementary to the normal Suzuki reaction.
Syntheses and photophysical properties of fluorescent dibenzofurans, a dibenzothiophene, and carbazoles substituted with benzoxazole and hydroxyl groups to produce excited state intramolecular proton-transfer
作者:Joel M. Kauffman、Peter T. Litak、Walter J. Boyko
DOI:10.1002/jhet.5570320523
日期:1995.9
Dibenzofurans, a dibenzothiophene, and carbazoles, each substituted with a 2-benzoxazolyl group as well as an ortho-hydroxyl group, were synthesized to produce fluors with fluorescence due to excited-state intramolecular proton-transfer. The orientations for Friedel-Crafts acylation of 3-methoxydibenzothio-phene and of the analogous carbazole were determined. The fluors displayed absorption peaks in
Biphenyl-substituted guanidine derivatives useful as hypoglycaemic agents
申请人:The Boots Company
公开号:US05302720A1
公开(公告)日:1994-04-12
Compounds of formula I ##STR1## and their salts in which R.sub.1 is optionally substituted phenyl, R.sub.2 is alkyl, cycloalkyl or optionally substituted amino, or R.sub.2 and R.sub.3 together with the nitrogen and carbon atoms to which they are attached form an optionally substituted heterocyclic ring or R.sub.3 and R.sub.4 together with the nitrogen atom to which they are attached form an optionally substituted heterocyclic ring and R.sub.5 is H, halo, alkyl, alkoxy, trifluoromethyl or a group of formula S(O).sub.m R.sub.8 in which m is 0, 1 or 2 and R.sub.8 is alkyl have utility in the treatment of diabetes particularly in the treatment of hyperglycaemia.