Palladium-Catalyzed Coupling of 3-Indolyl Triflate. Syntheses of 3-Vinyl and 3-Alkynylindoles
摘要:
Palladium-catalyzed coupling of 1 -(phenylsulfonyl)indol-3-yl trifluoromethanesulfonate (triflate) (1) with terminal alkenes and alkenes gives 3-vinyl (2) and 3-alkynylindoles in 45-93% yields. An attempt to generate 2,3-indolyne 22 from 2-trimethylsilyl-3-indolyl triflate 20 gives indigo (23).
C–H Alkenylation of Heteroarenes: Mechanism, Rate, and Selectivity Changes Enabled by Thioether Ligands
作者:Bradley J. Gorsline、Long Wang、Peng Ren、Brad P. Carrow
DOI:10.1021/jacs.7b03887
日期:2017.7.19
catalytic intermediate in these reactions may also account for unusual catalyst-controlled site selectivity wherein C–H alkenylation of five-atom heteroarenes can occur under electronic control with thioether ligands even when this necessarily involves reaction at a more hindered C–H bond. The thioether effect also enables short reaction times under mild conditions for many O-, S-, and N-heteroarenes (55 examples)
2-(1-Benzotriazolyl)pyridine: A Robust Bidentate Ligand for the Palladium-Catalyzed CC (Suzuki, Heck, Fujiwara-Moritani, Sonogashira), CN and CS Coupling Reactions
作者:Akhilesh K. Verma、Rajeev R. Jha、Ritu Chaudhary、Rakesh K. Tiwari、Abhinandan K. Danodia
DOI:10.1002/adsc.201200583
日期:2013.2.1
designed and employed for the palladium-catalyzed CC (Suzuki, Heck, Fujiwara–Moritani, and Sonogashira), CN and CS coupling reactions. The ligand was found to be inexpensive, thermally stable, easy to synthesize from easily accessible starting materials on a multigram scale, show simplicity in use, and robustness in application, making this ligand effective for different coupling reactions. Suitably, the
设计了一种新型的双齿配体1-(吡啶-2-基)-1 H-苯并[ d ] [1,2,3]三唑,并用于钯催化的CC(Suzuki,Heck,Fujiwara– Moritani和Sonogashira),CN和CS偶联反应。发现该配体便宜,热稳定,易于以几克规模由容易获得的起始原料合成,显示出使用简单性和在应用中的坚固性,从而使该配体对于不同的偶联反应有效。适当地,苯并三唑环的NN键的供体能力和吡啶环的N上的孤对电子增强了配体的二齿能力。
Microwave-Assisted, Aqueous Wittig Reactions: Organic-Solvent- and Protecting-Group-Free Chemoselective Synthesis of Functionalized Alkenes
作者:James McNulty、Priyabrata Das、David McLeod
DOI:10.1002/chem.201000438
日期:——
Free from protection! A general, chemoselective, protecting‐group‐ and organic‐solvent‐free route to stilbenes and heterostilbenes involving the direct synthesis of triethyl benzylic and allylic phosphonium salts from the corresponding alcohols and their microwave‐assisted, aqueous Wittig reactions is described.
Regioselective preferential C H activation of sterically hindered 1,3-dienes over [4+2] cycloaddition
作者:Rakesh K. Saunthwal、Kapil Mohan Saini、Monika Patel、Akhilesh K. Verma
DOI:10.1016/j.tet.2017.03.028
日期:2017.4
Pd-catalyzed preferential CH activation of sterically hindered α, β-olefinic indoles onto alkenes beyond [4 + 2] cycloaddition has been described. The carbazole derivatives were readily synthesized via activation of vinylic CH bonds with excellent regioselectivity. Further, the one-pot strategy has been employed for the synthesis of tricyclic carbazoles. The double and triple CH activation followed by concomitant
Palladium-Catalyzed Intermolecular C3 Alkenylation of Indoles Using Oxygen as the Oxidant
作者:Wen-Liang Chen、Ya-Ru Gao、Shuai Mao、Yan-Lei Zhang、Yu-Fei Wang、Yong-Qiang Wang
DOI:10.1021/ol302840b
日期:2012.12.7
A general and efficient palladium-catalyzedintermolecular direct C3 alkenylation of indolesusingoxygen as the oxidant has been developed. The reaction is of complete regio- and stereoselectivity. All products are E-isomers at the C3-position, and no Z-isomers or 2-substituted product can be detected.