Boronates, novel

The synthetic method used to accomplish this is an indirect one known as hydroboration-oxidation. It was developed by Professor Herbert C. Brown and his coworkers at Purdue University in the 1950s as part of a broad progran designed to apply boron-containing reagents to organic chemical synthesis. The number of applications is so large (hydroboration-oxidation is just one of them) and the work so novel that Brown was a corecipient of the 1979 Nobel Prize in chemistry. 

As a result of the systematic application of coordination-chemistry principles, dozens of previously unsuspected stnicture types have been synthesized in which polyhedral boranes or their anions can be considered to act as ligands which donate electron density to metal centres, thereby forming novel metallaboranc elusters, ". Some 40 metals have been found to act as acceptors in this way (see also p. 178). The ideas have been particularly helpful m emphasizing the close interconnection between several previously separated branches of chemistry, notably boron hydride clu.ster chemistry, metallaboranc and metallacarbaborane chemistry (pp. 189-95). organometallic chemistry and metal-metal cluster chemistry. All are now seen to be parts of a coherent whole. 

Application of vinyl boronate CM in epothilone chemistry, leading to epo490 (240d, a naturally occurring minor cometabolite, cf Scheme 49) and to novel 11-hydroxy and 11-fluoro analogs of epoD (Scheme 64), was reported by Dani-... 

Scheme 64 CM with vinyl boronate 327 in novel syntheses of epo490 (240d) and 11 -hydroxy analogs 332 and 333 of epoD [146]...

Novel boron-gold bonds containing complexes are realized in two borido clusters. Addition of [HFe4(CO)i2BH] ppn to xs (PPhjIAuCl in CH2CI2 forms the green-brown, air-sensitive Fe4(CO) 2(AuPPh,)2BH ... 

Conrad O, Jansen C, Krebs B (1998) Boron - Sulfur and Boron - Selenium compounds -From unique molecular structural principles to novel polymeric materials. Angew Chem IntEd37 3208-3218... 

A novel zinc porphyrin dimer (52) with a boronic ester linkage was prepared by Shinkai (Fig. 18) (65). The authors introduced an additional... 

Petasis reported an efficient addition of vinyl boronic acid to iminium salts.92 While no reaction was observed when acetonitrile was used as solvent, the reaction went smoothly in water to give allyl amines (Eq. 11.54). The reaction of the boron reagent with iminium ions generated from glyoxylic acid and amines affords novel a-amino acids (Eq. 11.55). Carboalumination of alkynes in the presence of catalytic Cp2ZrCl2 and H2O affords vinylalane intermediates, which serve as nucleophiles in the subsequent addition to enantiomerically enriched... 

Neutral borabenzene-PMe3, generated through the route described in Scheme 2, reacts with a variety of anionic nucleophiles to furnish 5-substituted borataben-zenes (Scheme 7).15 This approach provides efficient access to boratabenzenes that bear a range of boron substituents (H, C, N, O, P) with diverse electronic and steric properties.16 Mechanistic studies establish that this novel aromatic substitution process follows an addition-elimination pathway. 

NLO materials (16 and 17) (Fig. 13) have been obtained from polyurethanes by the incorporation of sidechains with boron chromophores.37 The dihydroxy ligand of an azobenzene ligand containing a dimesityl boron acceptor was reacted in a polycondensation fashion with the diisocyanate groups of the polyurethanes to yield the desired polymers. Halogen displacement and transmetallation reactions have been utilized in the development of extended ir-conjugated systems of tri-9-anthrylborane with dendritic structures.38 In one (18) (Fig. 14) of the novel compounds, three identical... 

Poly(boronic carbamatejs were prepared by alkoxyboration polymerization of diisocyanates with mesityldimethoxyborane (scheme 33).59 The polymers obtained have boronic carbamate functions in their repeating units and can be expected to be novel reactive polymers. First, alkoxyboration polymerization between mesityldimethoxyborane and 1,6-hexamethylene diisocyanate was examined, and the optimized reaction conditions were bulk reactions at 140°C. Both aliphatic and aromatic diisocyanates gave the corresponding polymers. When aromatic diisocyanates were employed, the... 

As a further approach for novel electrolytes appropriate for selective cation transport, we have prepared poly(organoboron halide)-imidazole complexes.35 Even though boron-amine complexes are widely known materials reported by the early works of H. C. Brown et al.,52-54 they had not been investigated as solvents or electrolytes to the best of our knowledge. 

Recently, novel polymethine carbonyl-dyes based on coumarin moiety and their boron difluoride complexes 9a-d and lOa-d [34—36] were evaluated as fluorescent dyes for the detection of native proteins using bovine serum albumin (BSA) as a model protein, and as probes for the nonspecific detection of proteins using a BSA/ sodium dodecyl sulfate (SDS) mixture [37]. Optical properties of these compounds in the absence and presence of BSA, as well as in SDS and BSA/SDS mixture, were measured in Tris-HCl buffer (pH 8.0) (Table 1). 

The reaction of Co2(CO)8 with 25 is complicated at room temperature, but above 60°C Co(CO)2(C5H5BPh) (11) is obtained as the only complex product (29). Ni(CO)4 reacts with 25 in boiling hexane to give the (cyclopentadienyl)(cyclopentenyl)nickel analog 49 [5(nB) = 24.4 ppm, one broad signal] this complex contains a novel boron-carbon ligand with... 

As the end-user in the NATO SfP project Carbons as materials for the electrochemical storage of energy Central Laboratory of Batteries and Cells does research and development works on the application of novel carbonaceous materials to the Li-ion technology. The general idea of these works is to build prototypes of cylindrical Li-ion cells on the basis of materials produced in the cooperating laboratories. The aim of this paper is to examine the applicability of selected commercial and non-commercial carbon materials (with special attention devoted to boron-doped carbons) to the construction of a practical cylindrical Li-ion cells. 

Stolowitz, M.L., Ahlem, C., Hughes, K.A., Kaiser, R.J., Kesicki, E.A., Li, G., Lund, K.P., Torkelson, S.M., and Wiley, J.P. (2001) Phenylboronic acid-salicylhydroxamic acid bioconjugates. 1. A novel boronic acid complex for protein immobilization. Bioconjugate Chem. 12, 229-239. 

The reaction of 1 with the boron trihalides BC13 and BBr3 turned out to be even more complex. At least three different types of compounds were formed, and the product ratio depended on the polarity of the solvent.30 In the reaction with BBr3 in dichloromethane/hexane (2 1), the boron compound 50 (X = Br) was isolated as the main product (Scheme 12) X-ray crystal structure analysis revealed the presence of a novel arachno-type cluster possessing a BC4 framework (Fig. 8). 

Structurally novel /3-lactams were obtained using enantiopure 4-oxoazetidine-2-carbaldehydes and methylene cyclohexane and a-methyl styrene (Equation (4)).7 Boron trifluoride diethyletherate and tin(iv) chloride produced the products in the highest yields, and all ene products possessed yy/z-stereochemistry. 

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