2042-85-5Relevant articles and documents
Synthesis of Biaryl, Arylamine and Aryl Ketone Compounds Using a Commercially Available Air- and Moisture-Stable Palladium Catalyst
Marion, Nicolas,Navarro, Oscar,Kelly III, Roy A.,Nolan, Steven P.
, p. 2590 - 2592 (2003)
A commercially available palladium complex bearing a N-heterocyclic carbene (NHC) was used in gram-scale synthesis of three compounds, a biaryl, an arylamine and an aryl ketone. The syntheses were performed in catalytic fashion using a Suzuki-Miyaura, a B
Highly Ambiphilic Room Temperature Stable Six-Membered Cyclic (Alkyl)(amino)carbenes
Weinstein, Cory M.,Junor, Glen P.,Tolentino, Daniel R.,Jazzar, Rodolphe,Melaimi, Mohand,Bertrand, Guy
, p. 9255 - 9260 (2018)
Cyclic (alkyl)(amino)carbenes with a six-membered backbone were prepared. Compared to their five-membered analogues, they feature increased %Vbur and enhanced donor and acceptor properties, as evidenced by the observed n → π? transition trailin
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Ashby,E.C. et al.
, p. 1221 - 1232 (1979)
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A comparative mechanistic analysis of the stereoselectivity trends observed in the oxidation of chiral oxazolidinone-functionalized enecarbamates by singlet oxygen, ozone, and triazolinedione
Sivaguru,Poon, Thomas,Hooper, Catherine,Saito, Hideaki,Solomon, Marissa R.,Jockusch, Steffen,Adam, Waldemar,Inoue, Yoshihisa,Turro, Nicholas J.
, p. 10647 - 10659 (2006)
The stereoselectivity in the reactions of the E/Z enecarbamates 1, equipped with the oxazolidinone chiral auxiliary, has been examined for singlet oxygen (1O2), ozone (O3), and 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) in
Stable cyclic (alkyl)(amino)carbenes as rigid or flexible, bulky, electron-rich ligands for transition-metal catalysts: A quaternary carbon atom makes the difference
Lavallo, Vincent,Canac, Yves,Praesang, Carsten,Donnadieu, Bruno,Bertrand, Guy
, p. 5705 - 5709 (2005)
(Chemical Equation Presented) Like NHCs? Not quite: Cyclic (alkyl)-(amino)carbenes (CAACs) are strong σ-donors and have steric environments that differ dramatically from those of bulky, electron-rich phosphines (A) and cyclic diaminocarbenes (B). These re
Anodic oxidation triggered divergent 1,2- And 1,4-group transfer reactions of β-hydroxycarboxylic acids enabled by electrochemical regulation
Jiang, Yangye,Lu, Gang,Mo, Fanyang,Yang, Jianxin,Yang, Yang,Yin, Yunxing,Zeng, Chengchu,Zhang, Lei,Zhang, Xianhao,Zhang, Zhenxing
, p. 12021 - 12028 (2020)
We report a set of electrochemically regulated protocols for the divergent synthesis of ketones and β-keto esters from the same β-hydroxycarboxylic acid starting materials. Enabled by electrochemical control, the anodic oxidation of carboxylic acids proceeded in either a one-electron or a two-electron pathway, leading to a 1,4-aryl transfer or a semipinacol-type 1,2-group transfer product with excellent chemoselectivity. The 1,4-aryl transfer represents an unprecedented example of carbon-to-oxygen group transfer proceeding via a radical mechanism. In contrast to previously reported radical group transfer reactions, this 1,4-group transfer process features the migration of electron-rich aryl substituents. Furthermore, with these chemoselective electrochemical oxidation protocols, a range of ketones and β-keto esters including those possessing a challenging-to-access medium-sized ring could be synthesized in excellent yields. This journal is
IPr# - highly hindered, broadly applicable N-heterocyclic carbenes
Flach, Carol,Lalancette, Roger,Li, Guangchen,Mendelsohn, Richard,Meng, Guangrong,Szostak, Michal,Szostak, Roman,Zhao, Qun
, p. 10583 - 10589 (2021/08/20)
IPr (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) represents the most important NHC (NHC = N-heterocyclic carbene) ligand throughout the field of homogeneous catalysis. Herein, we report the synthesis, catalytic activity, and full structural and electronic characterization of novel, sterically-bulky, easily-accessible NHC ligands based on the hash peralkylation concept, including IPr#, Np# and BIAN-IPr#. The new ligands have been commercialized in collaboration with Millipore Sigma: IPr#HCl, 915653; Np#HCl; 915912; BIAN-IPr#HCl, 916420, enabling broad access of the academic and industrial researchers to new ligands for reaction optimization and screening. In particular, the synthesis of IPr# hinges upon cost-effective, modular alkylation of aniline, an industrial chemical that is available in bulk. The generality of this approach in ligand design is demonstrated through facile synthesis of BIAN-IPr# and Np#, two ligands that differ in steric properties and N-wingtip arrangement. The broad activity in various cross-coupling reactions in an array of N-C, O-C, C-Cl, C-Br, C-S and C-H bond cross-couplings is demonstrated. The evaluation of steric, electron-donating and π-accepting properties as well as coordination chemistry to Au(i), Rh(i) and Pd(ii) is presented. Given the tremendous importance of NHC ligands in homogenous catalysis, we expect that this new class of NHCs will find rapid and widespread application.
COMPLEXES OF N-HETEROCYCLIC CARBENES FOR TRANSITION METAL CATALYSIS
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Paragraph 34, (2021/07/17)
Described herein is a new class of highly active Pd(II)-NHC complexes bearing anilines as throw-away ligands. These catalysts are well-defined, air- and moisture-stable and can be easily purified by chromatographic techniques. High activity and generality has been exemplified in the Suzuki-Miyaura cross-coupling by C-N, C-O and C-Cl cleavage. Facile syntheses of these catalysts is also described.
