Benzimidazoles 2-metallation

Benzenemethanethiol,a-(selenylmethylene)-metal complexes, 809 Benzeneselenic acid metal complexes, 807 Benzenetetrathiols metal complexes, 606 Benzenethiol, 2-amino-metal complexes, 799 Benzenethiol, o-hydroseleno-metal complexes, 809 Benzimidazole, 2-guanidinium-metal complexes, 283 Benzimidazole, 2-mercapto metal complexes, 802 Benzimidazole, 2-(2-pyridyl)-metal complexes, 93 Benzimidazoles metal complexes, 78, 85 P a, 11... 

Barbituric acid, methyl-5-nitroso-zinc complexes, 958 Bayldonite, 960 Benzeneselenic acid metal complexes, 977 Benzimidazole metal complexes, 949 Benzoquinoline zinc complexes, 953 Benzothiazole zinc complexes, 981 Benzotriazole zinc complexes, 950 Benzoxazole metal complexes, 951 Berry twist... 

Benzimidazole, 2-alkoxy-l-methyl-transalkylation, 5, 443 Benzimidazole, 1-alkyl-metal derivatives, 5, 448 reactions... 

Benzimidazole, 2-amino-5-bromo-l-methyl-diazo coupling, 5, 429 Benzimidazole, 2-amino-6-bromo-1 -methyl-diazo coupling, 5, 429 Benzimidazole, 2-amino-1-ethyl-alkylation, 5, 438 Benzimidazole, 2-amino-1-methyl-acylation, 5, 438 bromination, 5, 429 tautomerism, 5, 368 Benzimidazole, 4-amino-2-methyl-diazo coupling, 5, 429 Benzimidazole, 2-aroyl-mass spectra, 5, 360 Benzimidazole, 1-aryl-metallation, 5, 448 reactions... 

The vinyl group has been used to protect the nitrogen of benzimidazole during metalation with lithium diisopropylamide. It is introduced with vinyl acetate [Hg(OAc)2, H2SO4, reflux, 24 h] and cleaved by ozonolysis (MeOH, —78°). ... 

Stabilization of a metal-substituted derivative of a minor tautomeric form of the Ugand was reported for the complexes of mixed benzothiazo-line-benzimidazole (388 —> 389) (71ZOB1370 98POL381) and benzothia-zoline-pyridine ligands (390 —> 391/392) (Scheme 144) (77JA7704). 

The highly selective nitration of 6 set the stage for the installation of the benzimidazole as well as solving the problem of the biaryl ether formation, which would have been a challenge for existing transition metal-catalyzed technologies. 

Carbenes are defined as molecular species with formally divalent and two-coordinate carbon atoms bearing various substituents X and Y and a lone pair of electrons. While the simple representatives are of low stability (such as CH2) and may only appear as short-lived reaction intermediates or in adducts with electron donors, some cyclic systems can be readily isolated. This is particularly true for many of the A-heterocyclic carbenes (NHCs), which are now widely applied as ligands to metals ( Wanzlick-Arduengo carbenes ). Such carbenes based on imidazol and benzimidazol have become the working horses in this branch of organogold chemistry (Scheme 54). 

Benzimidazole derivatives are excellent antioxidants, with limited fatigue activity. They offer excellent metal poison protection. 

Major advancements in the chemistry of pyrazoles, imidazoles, triazoles, tetrazoles, and related fused heterocyclic derivatives continued in 2000. Solid-phase combinatorial chemistry of pyrazoles and benzimidazoles has been particularly active. Synthetic routes to all areas continue to be pursued vigorously with improvements and applications. Notably, metal-promoted and cross-coupling reactions of all classes seemed to be a dominant theme in 2000. Applications of pyrazole-, imidazole-, and 1,2,3-benzotriazole-containing reagents to a wide array of synthetic applications remained active. 

Other metal chelate materials of ligands such as benzimidazole have been disclosed in a Kodak patent as their beryllium or aluminum complexes (244) [271]. These materials generate very pure blue color within CIE range of (0.15-0.16, 0.12-0.17) [154,272]. 

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