Direct allenol-based stereocontrolled access to substituted (E)-1,3-enynes
作者:Benito Alcaide、Pedro Almendros、Teresa Martínez del Campo
DOI:10.1039/c2ob26085a
日期:——
A stereoselective synthesis of 1-substituted (E)-2-aryl-but-1-en-3-ynes, including tetrasubstituted alkenes, has been developed from aryl-substituted α-allenols by treatment with the AcCl–NaOH (aqueous) system. This transformation might be explained through the elimination of acetic acid, made up of a δ-hydrogen and the acetate group in the initially formed α-allenic acetate.
Carbonyl Allenylations andPropargylations by 3-Chloro-1-propyne or 2-Propynyl Mesylateswith Tin(IV) Chloride and Tetrabutylammonium Iodide
作者:Yoshiro Masuyama、Akiko Watabe、Yasuhiko Kurusu
DOI:10.1055/s-2003-41012
日期:——
By the use of tin(IV) chloride and tetrabutylammonium iodidein dichloromethane, 3-chloro-1-propyne or 2-propynyl mesylate canbe applied to allenylation and propargylation of aldehydes (carbonylallenylation and propargylation) to produce a mixture of 1-substituted2,3-butadien-1-ols and 1-substituted 3-butyn-1-ols. 1-Substituted2-propynyl mesylates selectively cause carbonyl propargylation,while 3-substituted 2-propynyl mesylates cause carbonyl allenylation.
Carbonyl propargylation by 1-substituted prop-2-ynyl mesylates and carbonyl allenylation by 3-substituted prop-2-ynyl mesylates with tin(ii) iodide and tetrabutylammonium iodide
1-Substituted prop-2-ynyl mesylates cause propargylation of aldehydes with tin(II) iodide, tetrabutylammoniumiodide and sodium iodide in 1,3-dimethylimidazolidin-2-one to produce 2-substituted but-3-yn-1-ols, while 3-substituted prop-2-ynyl mesylates cause allenylation of aldehydes under the same conditions as those of the propargylation by 1-substituted prop-2-ynyl mesylates to produce 2-substituted
Regioselective Addition Reactions of Propargyl Bromides to Carbonyl Compounds with Gallium Catalyzed by Indium
作者:Phil Ho Lee、Hyun Kim、Kooyeon Lee
DOI:10.1002/adsc.200505046
日期:2005.7
propargyl bromides having substituents at the γ-position and gallium in the presence of 5 mol % of indium with aldehydes and ketones selectively produced homoallenyl alcohols in good to excellent yields. Treatment of organogallium reagents obtained from propargyl bromide or propargyl bromides having substituents at the α-position and gallium in the presence of 5 mol % of indium with carbonyl compounds selectively