In(OTf)3-mediated synthesis of substituted pyridazines
摘要:
In(OTf)(3) (4c)-mediated one-pot (4+2) cyclocondensation of gamma-alkynones 3 with N2H4(aq) in dioxane affords substituted pyridazines 5 in good yields via a sequential desulfonative or dehydrogenative aromatization. The facile transformation proceeds by a facile synthetic sequence starting with an alpha-propargylation of beta-ketosulfones 1 and a cyclocondensation of gamma-alkynones 3 with N2H4(aq). The method provides a mild and efficient condition. Moreover, this route can be enlarged to multigram scale. (C) 2015 Elsevier Ltd. All rights reserved.
Base catalysed rearrangements involving ylide intermediates. Part 11. Rearrangements of 3-phenylprop-2-ynylammonium ylides
作者:Sivapathasuntharam Mageswaran、W. David Ollis、Dolores A. Southam、Ian O. Sutherland、Yodhathai Thebtaranonth
DOI:10.1039/p19810001969
日期:——
novel [1,3] rearrangementinvolving the migration of a dimethylamino-group. The basecatalysedrearrangements of the bicyclic propynylammonium salts (52) and (56) do not show the inhibition expected for concerted [3,2] sigmatropic rearrangements in such bicyclic systems. This observation provides further evidence for a two-stage mechanism for the apparent [3,2] sigmatropic rearrangement of propynylammonium