Saline hydrides and superbases in organic reactions. IX. Acetylene zipper. Exceptionally facile contrathermodynamic multipositional isomeriazation of alkynes with potassium 3-aminopropylamide
Relative Rates of Hydrosilylation of Representative Alkenes and Alkynes by Cp*<sub>2</sub>YMe·THF and [Cp<sup>TMS</sup><sub>2</sub>YMe]<sub>2</sub>
作者:Gary A. Molander、Elizabeth E. Knight
DOI:10.1021/jo9809027
日期:1998.10.1
Reactivity in the hydrosilylation of alkenes and alkynes catalyzed by the organoyttrium catalysts Cp(2)YMe.THF and [Cp(TMS)(2)YMe](2) is generally determined by the steric environment of the substrate. Alkynes and conjugated alkenes show an increased reaction rate because of electronic effects; the magnitude of this increase is highly substrate dependent. The electron rich pyrrole system is particularly
An insight into regioselectivity in the transformation through a ruthenacycle
作者:Sayori Kiyota、Masafumi Hirano
DOI:10.1039/c9nj04880d
日期:——
with conjugated dienes yields two conjugatedtriene products depending on the regioselectivity of the C–C bond formation reaction via a ruthenacycle intermediate. The electronic and steric effects of alkynes are comprehensively evaluated based on Hammett's (σp) and Taft's (σ*, Es) substituent constants. An electron-withdrawing substituent favours the external position of the conjugatedtriene products
Vinylic organoboranes. 1. A convenient synthesis of acetylenes via the reaction of lithium (1-alkynyl) organoborates with iodine
作者:Akira Suzuki、Norio Miyaura、Shigeo Abiko、Mitsuomi Itoh、M. Mark Midland、James A. Sinclair、Herbert C. Brown
DOI:10.1021/jo00374a002
日期:1986.11
Convenient and general synthesis of acetylenes via the reaction of iodine with lithium l-alkynyltriorganoborates
作者:Akira. Suzuki、Norio. Miyaura、Shigeo. Abiko、Mitsuomi. Itoh、Herbert C. Brown、James A. Sinclair、M. Mark. Midland
DOI:10.1021/ja00790a092
日期:1973.5
Arylsulfonylacetylenes as Alkynylating Reagents
作者:Leyre Marzo、José Alemán、José Luis García Ruano
DOI:10.1080/10426507.2012.748054
日期:2013.4.1
The unexpected anti-Michael addition of RLi to -substituted sulfonylacetylenes, followed by in situ elimination of the ion sulfinate, allows the alkynylation of C(sp(2)) and C(sp(3)). Aryl and heteroaryl acetylenes, enynes, and mono and dialkyl alkynes can be obtained in very high yields under very mild conditions, avoiding the use of transition metals as catalysts and, in many cases, haloderivatives as starting materials. Furthermore, the use of lithium 2-p-tolylsulfinyl benzylcarbanions as nucleophiles of these reactions allows their stereocontrolled alkynylation, affording enantiomerically pure alkynes or enantioenriched allenes depending on the protonating agent (NH4Cl or H2O).