The first controllable, regioselectiveradicalamination of allenes with N‐fluoroarylsulfonimide is described to proceed under very mild reaction conditions. With this methodology, a general and straightforward route for the synthesis of both allenamides and fluorinated tetrasubstitutedalkenes was realized from a wide range of terminal and internal allenes.
Tuning of Regioselectivity in the Coupling Reaction Involving Allenic/Propargylic Palladium Species
作者:Shengming Ma、Aibin Zhang
DOI:10.1021/jo0111098
日期:2002.4.1
Two different types of coupling patterns for the Pd(0)-catalyzed coupling reaction of allenic/propargylic zinc reagents with organic halides or propargylic carbonates (acetate) with the corresponding organometallicreagents were observed. After studying the controlling factors on the regioselectivity of this reaction, we demonstrated that the steric hindrance of both reactants and the types of organic
Highly Enantioselective Syntheses of Homopropargylic Alcohols and Dihydrofurans Catalyzed by a Bis(oxazolinyl)pyridine−Scandium Triflate Complex
作者:David A. Evans、Zachary K. Sweeney、Tomislav Rovis、Jason S. Tedrow
DOI:10.1021/ja011983i
日期:2001.12.1
Lewisacid promoted reactions of allylsilanes and allenylsilanes provide access to important building blocks for natural product synthesis. 1 For example, trimethylsilylallenes function as propargylic anion equivalents in aldehydeadditionreactions (eq 1, Path A).2 If the silicon center is sterically congested, the normal addition pathway is suppressed and functionalized dihydrofurans are produced
The rates of monometallation of alkylphenylacetylenes
作者:James Y. Becker
DOI:10.1016/s0022-328x(00)84192-3
日期:1977.2
Alkylphenylacetylenes, C6H5CCCH2R, have been metallated at the propargylic positions with an excess of n-butyllithium in diethyl ether at 0°C. Mono- and di-silyl derivatives have been isolated by quenching the metallation mixtures with Me3SiCl at different times. Pseudo-first order rate constants have been calculated for the monometallation from the rate of formation of the silylated products. A Taft
Organomagnesium-Catalyzed Isomerization of Terminal Alkynes to Allenes and Internal Alkynes
作者:Raphaël Rochat、Koji Yamamoto、Michael J. Lopez、Haruki Nagae、Hayato Tsurugi、Kazushi Mashima
DOI:10.1002/chem.201500179
日期:2015.5.26
the transformation of these terminalalkynes into allenes and further to internalalkynes under mild conditions. To the best of our knowledge, this example is the first of an organomagnesium‐catalyzed isomerization of alkynes. Notably, the reactions proceeded through temporally separated autotandem catalysis, thus allowing the isolation of the allene or internalalkyne species in good yields. Mechanistic