19472-74-3Relevant articles and documents
Divergent synthesis of CF3-substituted polycyclic skeletons based on control of activation site of acid catalysts
Yokoo, Kazuma,Mori, Keiji
, p. 6927 - 6930 (2018)
We report a divergent synthesis of CF3-substituted fused skeletons based on precise control of the activation site through the selection of acid catalysts. When trifluoromethyl ketones with an ortho-phenethyl ether group were treated with a catalytic amount of Sc(OTf)3, a hydride shift triggered C(sp3)-H bond functionalization proceeded to give CF3-substituted isochromene derivatives by selective activation of the carbonyl group. In sharp contrast, CF3-substituted bicyclo[3.3.1]nonanes were obtained exclusively via the activation of ether oxygen initiated sequential reactions (nucleophilic attack of carbonyl oxygen, and intramolecular Friedel-Crafts reaction) under strong Br?nsted acid catalysis (Tf2NH).
The palladium(ii)-catalyzed regioselective ortho-C-H bromination/iodination of arylacetamides with in situ generated imidic acid as the directing group: Mechanistic exploration
Jaiswal, Yogesh,Kumar, Yogesh,Kumar, Amit
, p. 6809 - 6820 (2019/07/22)
In the present study, we report the palladium(ii)-catalyzed regioselective ortho-C-H bromination/iodination of challenging arylacetamide derivatives using N-halosuccinimides as halogenating agents. Diverse arylacetamides underwent the regioselective ortho-bromination and iodination of aromatic C-H bonds in the presence of a reactive benzylic C(sp3)-H bond without installing any bulky auxiliaries via unfavorable six-membered metallacycles. Weak coordination, the use of ubiquitous primary amides for challenging C-H functionalization, the simple catalytic system and the wide substrate scope are the key features of this transformation. Further, the halogenated amide derivatives were transformed into a variety of valuable synthons. Detailed mechanistic studies revealed some interesting aspects concerning the reaction pathway. We present for the first time strong evidence for the formation of imidic acid (in situ) from primary amides under Br?nsted acid conditions that eventually aids in the stabilization of palladacycles of amide derivatives and drives regioselective C-X bond formation.
Construction of 1,3-Dithio-Substituted Tetralins by [1,5]-Alkylthio Group Transfer Mediated Skeletal Rearrangement
Hisano, Naoya,Kamei, Yuto,Kansaku, Yaoki,Yamanaka, Masahiro,Mori, Keiji
supporting information, p. 4223 - 4226 (2018/07/29)
A novel skeletal rearrangement involving a [1,5]-alkylthio group transfer/cyclization sequence is described. Treatment of benzylidene malonates having a thioketal moiety at the homobenzyl position with a catalytic amount of Sc(OTf)3 afforded alkylthio group rearranged adducts in good chemical yields. Detailed investigation of the reaction mechanism revealed that an intramolecular conjugate addition/ring opening sequence (not through-space transfer) is the key to achieving this reaction.
