Metal-Free Borane-Catalyzed Highly Stereoselective Hydrogenation of Pyridines
摘要:
A metal-free direct hydrogenation of pyridines was successfully realized by using homogeneous borane catalysts generated from alkenes and HB(C6F5)(2) via in situ hydroboration. The reaction affords a broad range of piperidines in high yields with excellent cis stereoselectivities.
Palladium-Catalyzed Cross-Coupling of Aryl Halides Using Organotitanium Nucleophiles
作者:Hang Wai Lee、Fuk Loi Lam、Chau Ming So、Chak Po Lau、Albert S. C. Chan、Fuk Yee Kwong
DOI:10.1002/anie.200904033
日期:2009.9.21
couple: Catalysts generated from Pd(OAc)2 and indolylphosphine ligands are highly effective in the titanium‐mediated coupling of arylhalides. Catalyst loadings as low as 0.05 mol % Pd can be used. The mild reaction conditions also allow the coupling of aryl sulfonyl chlorides with aryl titanium reagents to generate diaryl sulfones.
Iridium-Mediated Arylation of Quinoline via the Cleavage of Carbon–Carbon and Carbon–Nitrogen Bonds of 1,3-Dimesitylimidazol-2-ylidene
作者:Shun Sakurai、Mamoru Tobisu
DOI:10.1021/acs.organomet.9b00338
日期:2019.7.22
The iridium-mediated direct arylation of quinoline using an NHC ligand is reported. This reaction proceeds via cleavage of the carbon–carbon and carbon–nitrogen bonds of the NHC ligand and a carbon–hydrogen bond of quinoline.
A nickel-catalyzeddirectcross-coupling of unactivated aryl fluorides with aryl bromides is realized. The one-pot reaction, which avoids the use of preformed and sensitive organometallic reagents, proceeds effectively via C–F bond cleavage at room temperature in THF in the presence of the phosphine ligand and magnesium powder (with or without TMSCl) to produce the desired biaryls in modest to good
Rh(I)-Catalyzed Direct Arylation of Pyridines and Quinolines
作者:Ashley M. Berman、Jared C. Lewis、Robert G. Bergman、Jonathan A. Ellman
DOI:10.1021/ja8059396
日期:2008.11.12
A Rh(I)-catalyzed direct arylation of pyridine and quinoline heterocycles has been developed. The method provides rapid entry into an important class of substituted heterocycles employing inexpensive and readily available starting materials.