Lewis and Brønsted acid-mediated chemistry of alcohol pro-electrophiles as novel synthetic strategies for C-X (X = C, N, O) bond formation
Srinivasa Reddy Mothe
Date of Issue2012
School of Physical and Mathematical Sciences
The work in this thesis was undertaken at the Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University from August 2008 to June 2012 under the supervision of Asst. Prof. Philip Wai Hong Chan. The work of this thesis has been directed toward establishing new Lewis and Brønsted acid-catalyzed reactions of alcohol pro-electrophiles as novel synthetic strategies for C−X (X = C, N, O, S) bond formation. This thesis is divided into three parts: Part I consists of Chapter I, which gives an introduction of Lewis and Brønsted acid catalyzed reactions of alcohol pro-electrophiles, particularly those containing a pendant activated alcohols such as allylic, propargylic, benzylic and cyclopropylmethyl functional group. Part II describes the new strategies developed for C−X (X = C, N, O) bond formation employing alcohols as pro-electrophiles. Chapter II addressed highly efficient synthesis of tri- and tetrasubstituted conjugated enynes from Brønsted acid catalyzed alkoxylation of 1-cyclopropylprop-2-yn-1-ols with alcohols. In Chapter III, a novel strategy to halohydrofurans via Brønsted acid-catalyzed hydroxylation/halocyclization of cyclopropyl methanols with water and electrophilic halides is described. Chapter IV represented the silver triflate-catalyzed tandem heterocyclization/alkynylation of 1-((2-tosylamino)aryl)but-2-yne-1,4-diols to 2-alkynyl indoles. In Chapter V, a new method to tri- and tetrasubstituted furans via Brønsted acid-catalyzed cycloisomerization of but-2-yne-1,4-diols with or without 1,3-dicarbonyl vii compounds is disclosed. Chapter VI detailed silver-catalyzed tandem amination/spiro annulation of 1-(2-(allylamino)phenyl)-4-hydroxy-but-2-yn- -1-ones as an expedient approach to 1'-allylspiro[indene-1,2'-indolin]-3'-ones. Part III contains the experimental section (Chapter VII) and references section (Chapter VIII) pertaining to this thesis.
DRNTU::Science::Chemistry::Organic chemistry::Organic synthesis