Boron trialkyls oxide

BCl, BBr, and BI undergo exchange reactions to yield mixed boron hahdes. Exchange reactions also occur with trialkyl, triaryl, trialkoxy, or triaryloxy boranes and with diborane. Anhydrous metal bromides and iodides can be prepared by the exchange reaction of the metal chloride or oxide and BBr or BI (21)-... 

Boronic acids RB(OH)2 were first made over a century ago by the unlikely route of slow partial oxidation of the spontaneously flammable trialkyl boranes followed by hydrolysis of the ester so formed (E. Frankland, 1862) ... 

So far we have shown all reactions taking place on the monoalkyl borane. In fact, these compounds are unstable and most hydroborations actually occur via the trialkyl borane. Three molecules of alkene add to the boron atom three oxidations and three migrations transfer three alkyl groups (R = 2-methylcyclopentyl) from boron to oxygen to give the relatively stable trialkyl borate B(OR)3, which is hydrolysed to give the products. 

The base-induced reaction of dichloromethyl methyl ether with trialkyl- and triarylboranes also provides a powerful method for the preparation of the corresponding tertiary carbinols.16,17 In this case, all three groups transfer readily from boron to carbon under mild conditions, and oxidation with alkaline hydrogen peroxide provides the tertiary alcohol ... 

Since the boroxines are readily available from B203 and trialkyl boranes or trialkoxy boranes, they are in effect reactions of boron oxide with trialkyl alanes. Gallium tribromide and triethylalane give triethylgallane in over 80% yield, but only the first alkyl group on aluminum is involved in alkylation (63, 65) ... 

Low-molar-mass poly(butadiene) oils with 80%-97% cw-1,4 contents are produced with other Ziegler catalysts (for example, cobalt compounds with alkyl aluminum chlorides or nickel compounds with trialkyl aluminum and boron trifluoride-etherate). The products have few cross-links and dry as fast as wood oil and faster than linseed oil. Conversion of the poly (butadiene) oils with 20% maleic anhydride gives air-drying (air-hardening) alkyd resins. Modified poly (butadiene) oils stabilize erosion-endangered soils. Because of its low viscosity, the aqueous emulsion penetrates the surface soil layers. The surface crust is reinforced by an oxidative bonding process. Since no skin is formed on the soil crust, the aqueous absorption characteristics of the soil are retained. 

The polymerization o oxetanes with cationic catalysts has been studied by many investigators. (1.H2) RoseC. ), in particular, first reported the homopolymerization of the parent compound, tri-methylene oxide (TMO), with a Lewis acid catalyst, boron trifluoride. The use of coordination catalysts to polymerize oxetanes has been reported in the patent literature by Vandenberg.W In this work, Vandenberg polymerized oxetanes with the aluminum trialkyl -water-acetylacetone coordination catalyst (referred to as chelate catalyst) that he discovered for epoxide polymerization . This paper describes the homo- and co-polymerization of TMO with these coordination catalysts. Specific TMO copolymers, particularly with unsaturated epoxides such as allyl glycidyl ether (AGE), are shown to provide the basis for a new family o polyether elastomers. These new elastomers are compared with the related propylene oxide-allyl glycidyl ether (PO-AGE) copolymer elastomers. The historical development and general characteristics of polyether elastomers and, in particular, the propylene oxide elastomers, are reviewed below. 

Preparation.—Variations continue to appear on the theme of alcohol production by hydroboration-oxidation of olefins. 5-Methoxydialkylboranes react with olefins in the presence of lithium aluminium hydride to afford a new route to trialkylboranes and thence, by carbonylation-oxidation, to trialkylcarbinols. Carbonylation with carbon monoxide is avoided in a new procedure in the presence of an excess of trifluoroacetic anhydride, trialkyl cyanoborates undergo a triple alkyl migration from boron to carbon to give, on oxidation, high yields of trialkylcarbinols (Scheme 126). Tri-... 

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