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.
Trisulfur Radical Anion (S<sub>3</sub><sup>•–</sup>) Involved [1 + 2 + 2] and [1 + 3 + 1] Cycloaddition with Aromatic Alkynes: Synthesis of Tetraphenylthiophene and 2-Benzylidenetetrahydrothiophene Derivatives
作者:Jing-Hao Li、Qi Huang、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1021/acs.orglett.8b02066
日期:2018.8.3
S3•–-mediated [1 + 2 + 2] and [1 + 3 + 1] cycloaddition reactions of aromatic alkynes to give tetraphenylthiophene and 2-benzylidenetetrahydrothiophene derivatives via two C–S bond formations are developed. These two protocols provide new, simple, and straightforward strategies to construct tetraphenylthiophene and 2-benzylidenetetrahydrothiophene derivatives under transition-metal-free conditions
Gold-Catalyzed Oxidative Ring Expansions and Ring Cleavages of Alkynylcyclopropanes by Intermolecular Reactions Oxidized by Diphenylsulfoxide
作者:Chia-Wen Li、Kamalkishore Pati、Guan-You Lin、Shariar Md. Abu Sohel、Hsiao-Hua Hung、Rai-Shung Liu
DOI:10.1002/anie.201004647
日期:2010.12.17
A golden opportunity: A novel gold‐catalyzed oxidativering‐expansion of unactivated cyclopropylalkynes using Ph2SO has been developed (see scheme). For substrates bearing a donor group at the cyclopropane ring, preliminary results reveal a distinct cleavage of the cyclopropane unit; such a ringcleavage is further applicable to the synthesis of 2H‐pyrans. L=P(tBu)2(o‐biphenyl), Tf=triflate.
A heterogeneous gold(I)-catalyzed ring expansion of unactivated alkynylcyclopropanes with sulfonamides leading to (E)-2-alkylidenecyclobutanamines
作者:Feiyan Yi、Bin Huang、Quan Nie、Mingzhong Cai
DOI:10.1016/j.tetlet.2016.08.062
日期:2016.9
A heterogeneous gold(I)-catalyzed ringexpansion of unactivated alkynylcyclopropanes was achieved in 1,2-dichloroethane at 100 °C in the presence of sulfonamides by using a magnetic nanoparticle-supported phosphine gold(I) complex [Fe3O4@SiO2-P-AuOTf] as catalyst, yielding a variety of (E)-2-alkylidenecyclobutanamines in moderate to high yields. The new heterogeneous gold catalyst can easily be separated
通过使用磁性纳米粒子负载的膦金(I)络合物[Fe 3 O 4 @SiO] ,在磺酰胺存在下,在1,2-二氯乙烷中,在1,2-二氯乙烷中,未活化的炔基环丙烷在非均相的金(I)催化下扩环。2 -P-AuOTf]作为催化剂,以中等至高产率产生各种(E)-2-亚烷基亚环丁胺。通过施加外部磁体,可以轻松地从反应混合物中分离出新的多相金催化剂,并循环至少10次,而不会显着降低活性。