calcium‐catalyzed direct reduction of propargylic alcohols and ethers has been accomplished by using triethylsilane as a nucleophilic hydride source. At room temperature a variety of secondary propargylic alcohols was deoxygenated to the corresponding hydrocarbons in excellent yields. Furthermore, for the first time, a catalytic deoxygenation of tertiary propargylic alcohols was generallyapplicable. The
A Copper‐Catalyzed Sonogashira Coupling Reaction of Diverse Activated Alkyl Halides with Terminal Alkynes Under Ambient Conditions
作者:Yu‐Xi Cao、Xiao‐Yang Dong、Jun Yang、Sheng‐Peng Jiang、Shuangliu Zhou、Zhong‐Liang Li、Guo‐Qiang Chen、Xin‐Yuan Liu
DOI:10.1002/adsc.202000189
日期:2020.5.26
We describe a copper‐catalyzed Sonogashira coupling reaction of alkyl halides with terminalalkynesunder ambient conditions, efficiently providing a versatile tool for the construction of substituted alkynes. A new proline‐based N,N,P‐ligand is utilized to promote the transformation under a mild reaction condition. Diverse alkyl halides, such as primary and secondary (hetero)benzyl chlorides and bromides
Broadly Applicable Ion Pair-Assisted Nucleophilic Substitution of sp<sup>3</sup>-Carbon Electrophiles with Alkynyltrifluoroborates
作者:Shiwen Liu、Cláudio F. Tormena、Gerald B. Hammond、Bo Xu
DOI:10.1021/acs.orglett.2c02507
日期:2022.9.2
smoothly with a wide range of sp3-carbon electrophiles, including propargyl methanesulfonates and unactivated alkyl triflates, to give Sonogashira-type products, via a novel ion pair-assisted nucleophilicsubstitution mechanism. An ion pair–organic complex, investigated using computational chemistry and in situ NMR experiments, may play a crucial role in this reaction.
We have developed an efficient Cu/N,N-bidentate imine ligand catalytic system for C(sp3)–C(sp) coupling to obtain internal alkynes, di/trisubstituted allenes and strained bridged cyclic lactams in moderate to excellent yields from readily available alkyl(benzyl) bromides in one-pot transformation. Density Functional Theory (DFT) assisted mechanistic study along with control experiments support the