Synthesis of unsaturated 1,4-heteroatom-containing benzo-fused heterocycles using a sequential isomerization–ring-closing metathesis strategy
摘要:
A small library of 1,4-benzodioxins and 4H-1,4-benzoxazines was synthesized from the corresponding bis-allyloxy precursors by way of an initial isomerization to the bis-vinyloxy compounds, followed by a ring-closing metathesis using the second generation Grubbs' catalyst (G2). A related strategy, starting from benzene-1,2-dithiol and 2-mercaptophenol, afforded benzodithiin and 1,4-benzoxathiin, respectively. (C) 2009 Elsevier Ltd. All rights reserved.
Synthesis of unsaturated 1,4-heteroatom-containing benzo-fused heterocycles using a sequential isomerization–ring-closing metathesis strategy
摘要:
A small library of 1,4-benzodioxins and 4H-1,4-benzoxazines was synthesized from the corresponding bis-allyloxy precursors by way of an initial isomerization to the bis-vinyloxy compounds, followed by a ring-closing metathesis using the second generation Grubbs' catalyst (G2). A related strategy, starting from benzene-1,2-dithiol and 2-mercaptophenol, afforded benzodithiin and 1,4-benzoxathiin, respectively. (C) 2009 Elsevier Ltd. All rights reserved.
Process for the nucleophilic substitution of unactivated aromatic and heteroaromatic substrates
申请人:E.I. DU PONT DE NEMOURS AND COMPANY
公开号:EP0094821A1
公开(公告)日:1983-11-23
A process for achieving nucleophilic substitution upon an unactivated monocyclic or polycyclic aromatic or heteroaromatic substrate bearing a suitable leaving group comprising the substitution of said leaving group by an anionic nucleophile is catalyzed with a cyclic or acyclic polydentate chelating ligand, e.g. a crown ether or a cyclic polyether. The process is applicable, inter alia, as the first step in the preparation of ortho-substituted benzenesulfonyl chloride derivatives, or ortho-benzenedithiol, from ortho-dichlorobenzene.