76413-89-3Relevant academic research and scientific papers
Facile transformation of benzocyclobutenones into 2,3-benzodiazepines via 4π-8π tandem electrocyclic reactions involving net insertion of diazomethylene compounds
Matsuya, Yuji,Ohsawa, Noriko,Nemoto, Hideo
, p. 13072 - 13073 (2008/02/08)
Efficient transformations of benzocyclobutenones into 2,3-benzodiazepines by a formal insertion of diazomethylene compounds are described. This sequential process includes nucleophilic addition of diazomethylene anion, oxy-anion accelerated o-quinodimethane formation by an electrocyclic ring-opening reaction, and 8π-electrocyclization in one-pot under remarkably mild conditions. Intermediary oxy-anion plays an important role for the efficient transformations. Copyright
Transition-state effects in acid-catalyzed aryl epoxide hydrolyses
Sampson, Kyere,Paik, Augustine,Duvall, Bridget,Whalen, Dale L.
, p. 5204 - 5211 (2007/10/03)
The hydronium ion-catalyzed hydrolyses of 5-methoxyindene 1,2-oxide and of 6-methoxy-1,2,3,4-tetrohydronaphthalene-1,2-epoxide were each found to yield 75-80% of cis diol and only 20-25% of trans diol as hydrolysis products. The relative stabilities of the cis and trans diols in each system were determined by treating either cis or trans diols with perchloric acid in water solutions and following the approach to an equilibrium cis/trans mixture as a function of time. These studies establish that the trans diol in each system is more stable than the corresponding cis diol. Thus, acid-catalyzed hydrolysis of each epoxide, which proceeds via a carbocation intermediate, yields the less stable cis diol as the major product. Transition-state effects, presumably of a hydrogen-bonding nature, selectively stabilize the transition state for attack of water on the intermediate 2-hydroxy-1-indanyl carbocation leading to the less stable cis diol in this system. Transition-state effects must also be responsible for formation of the less stable cis diol as the major product in the acid-catalyzed hydrolysis of 5-methoxy-1,2,3,4-tetrahydronaphthalene 1,2-epoxide. However, in this system steric effects at the transition state may be more important than hydrogen bonding in determining the cis/trans diol product ratio. The synthesis of 5-methoxyindene 1,2-oxide and a study of its rate of reaction as a function of pH in water and dioxane-water solutions are reported. Both an acid-catalyzed reaction leading to only diol products and a pH-independent reaction yielding 71% of 5-methoxy-2-indanone and 29% of diols are observed; the half-life of its pH-independent reaction in water is only 2.4 s.
Novel guanidinobenzamides
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, (2008/06/13)
Compounds of formula IA and IB are new where the variables R1 through R10 have the values set forth herein. Such compounds have use in treating diseases such as obesity and type II diabetes, and may be provided as pharmaceutical form
An approach to 1-alkyl-3-phenylpiperidine derivatives containing 2,5- functionalized groups: 1-Methyl-2-(4-chlorophenylthiomethyl)-5- (metoxycarbonyl)-piperidine
Kotzamani,Gourdoupis,Stamos
, p. 10477 - 10482 (2007/10/02)
Compound 6 was synthesized by regiospecific addition of 4- chlorothiophenol to diazoketone 5 in the presence of a rhodium (II) acetate catalyst. An annelation process presumably proceeded via initial attack of methylamine on the bromoacrylic ester to give
