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
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。
BiCl<sub>3</sub>-Mediated direct functionalization of unsaturated C–C bonds with an electrophilic SCF<sub>2</sub>PO(OEt)<sub>2</sub> reagent
A transition metal-free approach was developed for the direct difunctionalization of disubstituted alkynes and terminal alkenes with concomitant formation of C–SCF2PO(OEt)2 and C–Cl bonds. The BiCl3-mediated reaction offered access to high value-added functionalized scaffolds in a single operation under mild conditions. Extension to SCF2PO(OEt)2-containing alkynes was also studied.
A facile and efficient copper-catalyzed azidative multifunctionalization of alkynes has been developed by using N-fluorobenzenesulfonimide (NFSI) as both nitrogensource and arylsource and trimethylsilyl azide (TMSN3) as azido source. This transformation proceeds under mild conditions, providing a series of α-azido-α-aryl imine in good yields by a single operation starting from a wide range of alkynes