Oxaphosphole-Based Monophosphorus Ligands for Palladium-Catalyzed Amination Reactions
作者:Sonia Rodriguez、Bo Qu、Nizar Haddad、Diana C. Reeves、Wenjun Tang、Heewon Lee、Dhileepkumar Krishnamurthy、Chris H. Senanayake
DOI:10.1002/adsc.201000878
日期:2011.3.7
A novel class of C‐2‐substituted oxaphosphole‐based monophosphines 1–4 has been synthesized. Palladium complexes derived from these ligands and their C‐2‐unsubstituted analogs provide general catalysts for aminationreactions of challenging aryl and heteroaryl halides with sterically hindered anilines and alkylamines.
Pd-Catalyzed Aryl Amination Mediated by Well Defined, N-Heterocyclic Carbene (NHC)–Pd Precatalysts, PEPPSI
作者:Michael G. Organ、Mirvat Abdel-Hadi、Stephanie Avola、Igor Dubovyk、Niloufar Hadei、Eric Assen B. Kantchev、Christopher J. O'Brien、Mahmoud Sayah、Cory Valente
DOI:10.1002/chem.200701621
日期:2008.3.7
Pd-N-heterocyclic carbene (NHC)-catalyzed Buchwald-Hartwig amination protocols mediated by Pd-PEPPSI precatalysts is described. These protocols provide access to a range of hindered and functionalized drug-like aryl amines in high yield with both electron-deficient and electron-rich aryl- and heteroaryl chlorides and bromides. Variations in solvent polarity, base and temperature are tolerated, enhancing
Efficient Pd-Catalyzed Amination of Heteroaryl Halides
作者:Mark D. Charles、Phillip Schultz、Stephen L. Buchwald
DOI:10.1021/ol0514754
日期:2005.9.1
The Pd-catalyzed amination of a variety of heteroaryl halides has been accomplished by utilizing bulky electron-rich biaryl phosphine ligands. In particular, we report the first couplings of amines with chloro- and bromoindoles bearing a free NH, as well as the first Pd-catalyzed aminations of a 5-halopyrimidine.
Buchwald‐Hartwig Amination of Coordinating Heterocycles Enabled by Large‐but‐Flexible Pd‐BIAN‐NHC Catalysts**
AbstractA new class of large‐but‐flexible Pd‐BIAN‐NHC catalysts (BIAN=acenaphthoimidazolylidene, NHC=N‐heterocyclic carbene) has been rationally designed to enable the challenging Buchwald‐Hartwig amination of coordinating heterocycles. This robust class of BIAN‐NHC catalysts permits cross‐coupling under practical aerobic conditions of a variety of heterocycles with aryl, alkyl, and heteroarylamines, including historically challenging oxazoles and thiazoles as well as electron‐deficient heterocycles containing multiple heteroatoms with BIAN‐INon (N,N′‐bis(2,6‐di(4‐heptyl)phenyl)‐7H‐acenaphtho[1,2‐d]imidazol‐8‐ylidene) as the most effective ligand. Studies on the ligand structure and electronic properties of the carbene center are reported. The study should facilitate the discovery of even more active catalyst systems based on the unique BIAN‐NHC scaffold.
A Visible-Light-Mediated Synthesis of Carbazoles
作者:Augusto C. Hernandez-Perez、Shawn K. Collins
DOI:10.1002/anie.201306920
日期:2013.11.25
The photosynthetic preparation of N‐aryl‐ and N‐alkyl‐bearing carbazoles utilizes continuousflow, visiblelight, and an in situ formed Cu‐based sensitizer (see picture). The method is mild and efficient, and allows the straightforward synthesis of a variety of carbazoles with different substituents, heterocycles, and complex carbon architectures.