Benzoxazole metal complexes

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... 

Coordination compounds of 2-hydrox3 henyloxazole are rarely studied, e.g., 350 (03CM4949). For a similar benzoxazole derivative, however, there are various metal complexes differing in the number of the chelate fragments. Mono-chelate coordination compounds include neutral platinum 351 (M = Pt, L = = Cl) (91BCJ149) and rhenium 352... 

Kumar, A., and D. Kumar. 2007. Synthesis and antimicrobial activity of metal complexes from 2-(172 -hydroxynaphthyl)benzoxazoles. Arkivoc 14 117-125. 

The recent developments on the metallation chemistry of oxazoles and benzoxazoles, isoxazoles and benzisoxazoles, pyrazoles and indazoles, thiazoles and benzo-thiazoles, and isothiazoles, benzo[c]isothiazoles, and benzoMisothiazoles have been reviewed. The two-decade history of catalytic carbon-carbon bond formation via direct borylation of alkane C-H bonds catalysed by transition metal complexes has been reported. The alkane functionalization via electrophilic activation has been underlined. " Recent advances of transition-metal-catalysed addition reactions of C-H bonds to polar C-X (X=N, O) multiple bonds have been highlighted and their mechanisms have been discussed. The development and applications of the transition metal-catalysed coupling reactions have been also reviewed. - ... 

Oxygen-containing azoles are readily reduced, usually with ring scission. Only acyclic products have been reported from the reductions with complex metal hydrides of oxazoles (e.g. 209 210), isoxazoles (e.g. 211 212), benzoxazoles (e.g. 213 214) and benzoxazolinones (e.g. 215, 216->214). Reductions of 1,2,4-oxadiazoles always involve ring scission. Lithium aluminum hydride breaks the C—O bond in the ring Scheme 19) 76AHC(20)65>. 

The tetrahydro-derivatives of the oxazole and isoxazole system are unstable. As a consequence, only acyclic products have been reported from the reductions with complex metal hydrides. 2,5-Diphenyl-oxazole (119) gave 2-benzylamino-l-phenylethanol (120),141 and 3,5-diphenyl-2-isoxazoline (121) was converted to 3-amino-l,3-diphenylpropanol (122)142 on reduction with lithium aluminum hydride. 3-Phenylbenzisoxazole was resistant to reduction with lithium aluminum hydride and sodium borohydride,143 but benz-oxazole (123), benzoxazol-2-one (124), and benzoxazol-2-thione (125) have been reported 141 to yield 2-methylaminophenol (126) on reduction with lithium aluminum hydride. 

The tridentate monobasic ligand l-(2-pyridylazo)-2-naphtholate (pan) has been used to prepare seven-coordinate complexes R2(pan)M(L) (L = ACAC derivative, M = Sn, R = Bu, Me M = Pb, R = Me). For both metals the difference in 8 is distinct from lower coordination numbers, both showing an upfield shift in b of ca. 200" typical for such a change in coordination number." The dianionic tetracyclic ligand (168) is prepared from the lithiation of 2-Me-benzoxazole and reacts with tin(II) chloride to form (169)." ... 

Benzoxazole (L) derivatives of the stoicheiometry M(XCN)2L2 (M = Zn or Cd X = S or Se) and Cd(NCSe)2L have been prepared the former are pseudotetrahedral while the latter is polymeric. The ligand is N-bonded in all cases. Benzoxazole-2-thione(L) forms the similar MX2L2 complexes (M = Zn, Cd, Hg X = Q, Br, I) and Cdl2L co-ordination is via nitrogen, and not sulphur or oxygen. The complexes ML2 (M = Zn or Cd) have been isolated from reaction of the metal acetate or nitrate with the iV,0-chelating 2-(o-hydroxyphenyl)benzoxazole (HL). ... 

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