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.
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
Ni-Catalyzed regio- and stereoselective addition of arylboronic acids to terminal alkynes with a directing group tether
作者:Madala Hari Babu、Gadi Ranjith Kumar、Ruchir Kant、Maddi Sridhar Reddy
DOI:10.1039/c6cc10256e
日期:——
Addition of arylboronic acids to directing group tethered acetylenes in a regio and stereoselective manner using an inexpensive catalytic system is achieved for the first time to access highly sought after allyl/homoallyl alcohol/amine units.
Direct, Catalytic Monofluorination of sp<sup>3</sup> C–H Bonds: A Radical-Based Mechanism with Ionic Selectivity
作者:Cody Ross Pitts、Steven Bloom、Ryan Woltornist、Dillon Jay Auvenshine、Lev R. Ryzhkov、Maxime A. Siegler、Thomas Lectka
DOI:10.1021/ja505136j
日期:2014.7.9
studies that, to our surprise, was revealed to be a radical chain mechanism in which copper acts as an initiator. Furthermore, we offer an explanation for the notable but curious preference for monofluorination by ascribing an ionic character to the transition state.
Theoretical Support for the Involvement of a Radical Pathway in the Formation of Allenylzincs from Propargyl Iodides and Dialkylzincs: Influence of Zinc Coordination
作者:Suribabu Jammi、Dominique Mouysset、Didier Siri、Michèle P. Bertrand、Laurence Feray
DOI:10.1021/jo302704g
日期:2013.2.15
undergo homolytic substitution at zinc. The stabilization of allenylzinc derivatives by chelation, made possible by the selection of appropriate ortho-substituted 3-phenylalkynyl iodides as precursors, was shown to influence the regioselectivity of their addition to aldehydes and ketones. The more stabilized the chelated allenylzinc intermediate, the higher the ratio of homopropargylic alcohols.