19995-19-8Relevant articles and documents
Regioselective synthesis of heterocycles containing nitrogen neighboring an aromatic ring by reductive ring expansion using diisobutylaluminum hydride and studies on the reaction mechanism
Cho, Hidetsura,Iwama, Yusuke,Sugimoto, Kenji,Mori, Seiji,Tokuyama, Hidetoshi
experimental part, p. 627 - 636 (2010/04/29)
(Chemical Equation Presented) A systematic investigation of the reductive ring-expansion reaction of cyclic ketoximes fused to aromatic ringswith diisobutylaluminum hydride (DIBALH) is described. This reaction regioselectively afforded a variety of five- to eight-membered bicyclic heterocycles or tricyclic heterocycles containing nitrogen neighboring an aromatic ring, including indoline, 1,2,3,4,5,6-hexahydrobenz[b]azocine, 3,4-dihydro-2H-benzo[b] [1,4]oxazine, 2,3,4,5-tetrahydrobenzo[b][1,4]thiazepine, 1,2,3,4,5,6- hexahydroazepino[3,2-b]-indole, 2,3,4,5-tetrahydro-1H-benzothieno[2,3-b]azepine, 2,3,4,5-tetrahydro-1H-benzothieno[3,2-b]-azepine, 5,6-dihydrophenanthridine, and 5,6,11,12-tetrahydrodibenz[b, f]azocine. The reaction mechanism leading to the rearrangement was investigated on the basis of the restricted Becke three-parameter plus Lee-Yang-Parr (B3LYP) density functional theory (DFT) with the 6-31G (d) basis set. It was found that the reaction proceeds through a three-centered transition state via a stepwise mechanism because the potential energy curve along the intrinsic reaction coordinate (IRC) had twomaxima (saddle points; TS1 and TS2) and the partial phenonium cation intermediate C. In addition to cyclic ketoximes fused to aromatic rings, the reactions of various cyclic and acyclic ketoximeswere examined to investigate preference of migrating group. It was found that themore electron-rich group migrated preferentially to give the corresponding secondary amines.
Further characterization of structural requirements for ligands at the dopamine D2 and D3 receptor: Exploring the thiophene moiety
Dijkstra, Durk,Rodenhuis, Nienke,Vermeulen, Erik S.,Pugsley, Thomas A.,Wise, Lawrence D.,Wikstr?m, H?kan V.
, p. 3022 - 3031 (2007/10/03)
The present study describes the synthesis and in vitro pharmacology of a novel series of dopaminergic agents in which the classical phenylethylamine pharmacophore is replaced by a thienylethylamine moiety. In general, the novel compounds showed a moderate
Regioselective synthesis of several heterocyclic fused azepines using diisobutylaluminum hydride
Cho, Hidetsura,Murakami, Kengo,Nakanishi, Hiroyuki,Isoshima, Hirotaka,Hayakawa, Kazuhide,Uchida, Itsuo
, p. 919 - 927 (2007/10/03)
5,6,7,8-Tetrahydrothieno[3,2-b]azepine,5,6,7,8-tetrahydro-1H-furo[3,2-b] azepine, and 1,4,5,6,7,8-hexahydropyrrolo[3,2-b]azepine were synthesized by the ring expansion reaction of heterocyclic fused cyclohexanone oximes with diisobutylaluminum hydride (DIBAH). The mechanism of the reaction was different from that of Beckmann rearrangement.
