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。
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.
A General Synthesis of Alkenyl‐Substituted Benzofurans, Indoles, and Isoquinolones by Cascade Palladium‐Catalyzed Heterocyclization/Oxidative Heck Coupling
作者:Rosana Álvarez、Claudio Martínez、Youssef Madich、J. Gabriel Denis、José M. Aurrecoechea、Ángel R. de Lera
DOI:10.1002/chem.201001535
日期:2010.11.8
consecutive Sonogashira and cascade Pd‐catalyzedheterocyclization/oxidativeHeckcouplings from readily available ortho‐iodosubstituted phenol, aniline, and benzamide substrates, alkynes, and functionalized olefins. The cyclization of O‐ and N‐heteronucleophiles follows regioselective 5‐endo‐dig‐ or 6‐endo‐dig‐cyclization modes, whereas the subsequent Heck‐type coupling with both mono‐ and disubstituted
Pd(II)-Catalyzed CH Activation of Styrylindoles: Short, Efficient, and Regioselective Synthesis of Functionalized Carbazoles
作者:Rakesh K. Saunthwal、Monika Patel、Sonu Kumar、Abhinandan K. Danodia、Akhilesh K. Verma
DOI:10.1002/chem.201503657
日期:2015.12.14
A novel PdII‐catalyzed approach for the direct synthesis of highly functionalized carbazoles from unprotected styrylindoles has been developed. The reaction features a variety of olefin substrates, which are readily switchable by subtle tuning of the reaction conditions. Investigations of the mechanism suggest that the CHactivation proceeds via enamine formation.