Copper‐Catalyzed Synthesis of Tetrasubstituted Alkenes via Regio‐ and
<i>anti</i>
‐Selective Addition of Silylboronates to Internal Alkynes
作者:Hirokazu Moniwa、Ryo Shintani
DOI:10.1002/chem.202100933
日期:2021.5.12
As a new and complementary method for the synthesis of structurally defined tetrasubstituted alkenes, a copper‐catalyzed regio‐ and anti‐selectiveaddition of silylboronates to unsymmetric internal alkynes has been developed. A variety of unactivated alkynes can be employed with high selectivity under simple and mild conditions, and the resulting products have been further functionalized by utilizing
Synthesis of α-heterosubstituted ketones through sulfur mediated difunctionalization of internal alkynes
作者:Zhong Zhang、Yuzheng Luo、Hongguang Du、Jiaxi Xu、Pingfan Li
DOI:10.1039/c9sc00568d
日期:——
Synthesis of α-heterosubstituted ketones was achieved through sulfur mediated difunctionalization of internal alkynes in one pot. The reaction design involves: phenyl substituted internal alkyne attacking triflic anhydride activated diphenyl sulfoxide to give a sulfonium vinyl triflate intermediate, hydrolysis to give an α-sulfonium ketone, and then substitution with various nucleophiles. This method
C(sp2)-C(sp) and C(sp)-C(sp) Coupling Reactions Catalyzed by Oxime-Derived Palladacycles
作者:Diego A. Alonso、Carmen Nájera、Ma Carmen Pacheco
DOI:10.1002/adsc.200303067
日期:2003.9
4′-dichlorobenzophenone, is an efficient pre-catalyst for the copper- and amine-free Sonogashira coupling between terminal acetylenes and aryl iodides and aryl and vinyl bromides achieving turnover numbers (TON) of up to 72000. Catalyst 8a has also been shown as a effective promoter for the sila-Sonogashira coupling between 1-(trimethylsilyl)alkynes and aryl iodides and bromides in the presence of CuI or
Visible‐Light‐Promoted Oxy‐difluoroalkylation of Aryl Alkynes for the Synthesis of
<i>β</i>
‐Fluoroenones and
<i>α</i>
‐Difluoroalkyl Ketones
作者:Zhong Zhang、Xiangqian Li、Dayong Shi
DOI:10.1002/adsc.202100289
日期:2021.7
synthesis of (E)-β-fluoroenones and α-difluoroalkyl ketones have been achieved. By employing water as oxygen source, potassium carbonate as base, tetrasubstituted β-fluoroenones could be regio- and stereoselectively synthesized by oxy-difluoroalkylation of alkynes under visible light irradiated with moderate to good yields. α-Difluoroalkyl ketones could be obtained while using phenylpyridine as base
一种选择性合成( E ) -β-氟烯酮和α-二氟烷基酮的方法已经实现。以水为氧源,碳酸钾为碱,在可见光照射下,炔烃的氧二氟烷基化反应可以区域选择性和立体选择性地合成四取代的β-氟代烯酮,收率适中。以苯基吡啶为碱可制得α-二氟烷基酮。这种改造具有条件温和、功能耐受性广、步骤经济等特点。大规模转化和进一步衍生化显示了其在有机合成中的潜在应用。
Regio- and Stereoselective Cyanotriflation of Alkynes Using Aryl(cyano)iodonium Triflates
作者:Xi Wang、Armido Studer
DOI:10.1021/jacs.6b00869
日期:2016.3.9
A novel, mild, and versatile approach for regioselective syn-addition of both the CN and OTf groups of aryl(cyano)iodonium triflates to alkynes is described. The reaction uses Fe-catalysis and can be conducted in gram scale. Products of the vicinal cyanotriflation can be stereospecifically readily further functionalized, rendering the method highly valuable.