Mono complexes boron

Later, Sasai et al. found that a combination of the heterobimetalhc complex boron-lithium-mono(binaphthoxide) (BLB) (380) and (Bu")3P is effective in promoting the enantioselective MBH reaction of cyclic enones with aldehydes via double activation to afford the adduct in good chemical yield with moderate to high enantioselectivity (Scheme 2.216) ... 

Organic ring systems are named by replacement nomenclature. Three- to ten-membered mono-cyclic ring systems containing uncharged boron atoms may be named by the specialist nomenclature for heterocyclic systems. Organic derivatives are named as outlined for substitutive nomenclature. The complexity of boron nomenclature precludes additional details the text by Rigaudy and Klesney should be consulted. 

Alkyl silyl ethers are cleaved by a variety of reagents Whether the silicon-oxygen or the carbon-oxygen bond is cleaved depends on the nature of the reagent used Treatment of alkoxysilanes with electrophilic reagents like antimony tri-fluonde, 40% hydrofluonc acid, or a boron tnfluonde-ether complex results in the cleavage of the silicon-oxygen bond to form mono-, di-, and tnfluorosiloxanes or silanes [19, 20, 21) (equations 18-20)... 

Compounds 167-171 outlined in Fig. 43 form another series of diboronic acids that form complexes with mono- and disaccharides. In these cases the asymmetrical immobilization of chromophoric functional groups, e.g., aromatic rings in 167-170 or Fe -complexation with the related boronate 171, can be analyzed by circular dichroism measurements [256-262]. 

The initiation reaction in the polymerization of vinyl ethers by BF3R20 (R20 = various dialkyl ethers and tetrahydrofuran) was shown by Eley to involve an alkyl ion from the dialkyl ether, which therefore acts as a (necessary) co-catalyst [35, 67]. This initiation by an alkyl ion from a BF3-ether complex means that the alkyl vinyl ethers are so much more basic than the mono-olefins, that they can abstract alkylium ions from the boron fluoride etherate. This difference in basicity is also illustrated by the observations that triethoxonium fluoroborate, Et30+BF4", will not polymerise isobutene [68] but polymerises w-butyl vinyl ether instantaneously [69]. It was also shown [67] that in an extremely dry system boron fluoride will not catalyse the polymerization of alkyl vinyl ethers in hydrocarbons thus, an earlier suggestion that an alkyl vinyl ether might act as its own co-catalyst [30] was shown to be invalid, at least under these conditions. 

Flow fluorination of the 4,4 -bipyridine —boron trifluoride complex gives only mono-fluorinated l-fluoro-4-(4-pyridyl)pyridinium boron trifluoride tetrafluoroborate (31), while fluorination of l-methyl-4-(4-pyridyl)pyridinium triflate in the presence of lithium triflate provides l-fluoro-l -methyl-4,4 -bipyridinium ditriflatc (32) 67... 

Substitution of hydrogen by fluorine in compounds with acidic a-hydrogens can be achieved with xenon difluoride and some catalysts. Thus, room-temperature fluorination of 1,3-diketones, e g. 20, with xenon difluoride in the presence of the insoluble cross-linked polysty-rene-4-vinylpyridine, either complexed with boron trifluoridc or Nafion-H, as catalyst, gives mono and difluoro products.27-28... 

Alkyl nitrites can also be used in anhydrous media and, for example, 4-hydroxyben-zenediazonium tetrafluoroborate is isolated in 89% yield after diazotization with isopcntyl nitrite, hydrogen fluoride and boron trifluoride in ethanol/diethyl ether.96 Diazotization can also be performed in dichloromethane or ethers (diethyl ether, tetrahydrofuran, 1,2-dimethoxyethane) with terl-butyl nitrite and boron trifluoride-diethyl ether complex which generates nitrosyl fluoride in situ.229 Excess boron trifluoride is used to trap water and tert-butyl alcohol, so that the reaction can be considered as being performed under complete anhydrous conditions. Yields are higher in dichloromethane, but 1,2-dimethoxyethane is preferred for less soluble amines. This procedure has been successfully applied to the synthesis of mono-and difluorobenzo[c]phcnanthrenes.230... 

Although boron carbonyls are only stable at very low temperature, H3BCO reacts with hydroxide to give [H3BC02 2. which is stable at room temperature and is normally isolated as the mono sodium salt, Na[H3BC02H] [212], It was patented as a source of CO source for preparation of transition metal carbonyl complexes [213]. It is also a good source of CO for medical applications [214], It readily releases CO at physiological pH. 

Alkylphenol. Alkylphenol is a common surfactant intermediate used to produce alkylphenol ethoxylates. Phenol reacts with an olefin thermally without a catalyst but with relatively poor yields. Catalysts for the reaction include sulfuric acid p-toluene sulfonic acid (PTSA), strong acid resins, and boron trifluoride (BF3). Of these, strong acid resins and BF3 are mostly widely used for the production of surfactant-grade alkylphenols. The most common alkylphenols are octylphenol, nonylphenol, and dodecylphe-nol. Mono nonylphenol (MNP) is by far the most common hydrophobe. It is produced by the alkylation of phenol with nonene under acid conditions. All commercially produced MNP is made with nonene based on propylene trimer. Because of the skeletal rearrangements that occur during propylene oligomerization, MNP is a complex mixture of branched isomers. 

A new class of boron compounds has been prepared by the reaction of pentacarbonyliron with dichloro(dimethylamino)borane to form (CO)4FeBN(CH3)2, a borylene complex.10 The mono- and dihaloamino-boranes can be prepared from the corresponding tris(amino)borane.11,12 Pyrolysis of the tris(primary amino)borane B(NHR)3 yields the borazine B3(NHR)3N3R3.3... 

The redox properties of macrobicyclic iron(II) mono- and binuclear oximehydrazonates and a-dioximates formed by capping with antimony(V) and germanium(IV) triorganyles were studied by cyclic voltammetry [73, 74]. The electrochemical behaviour of these compounds is similar to that of analogous boron- and tin-capped clathrochelates. Oxidation of all mononuclear complexes involves a one-electron process, assigned to the oxidation of encapsulated iron(II) ion to iron(III) ion. This process is electrochemically... 

Ethane- and propane-1,2-dithiolato Cp titanium derivatives have been reported. They are reduced by boron and tin hydrides.1013,1014 Mono-Cp titanium(iv) sulfido complexes have been made by treatment of CpTiCl3 with dithiols in the presence of donor ligands such as imidazole or PMe3 under different reaction conditions (Scheme 418).1015 The structures of the compounds have been reported. Electrochemical studies suggest that these compounds are formed through a radical mechanism.1016... 

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