Organoboron boranes

A novel and far-reaching type of isomerism concerns the possibility of valence isomerism between nonclassical (electron-deficient) clusters and classical" organoboron structures. Thus, n-vertexed /do-boranes. have cluster structures... 

An alkyl- or alkenylboron compound, as a suitable organoboron component (a borane, boronic acid or ester) can be prepared through hydroboration of an... 

L Monomeric and Polymeric Organic Analogs of Boron Cluster Systems The polyhedral clusters of boranes and carboranes are groups of cluster systems that are present ubiquitously in organoboron polymers. As in the case with the... 

Hydroboration polymerization between diene monomers and 2,4,6-trimethylphenylborane (mesitylborane)6 or 2,4,6-triisopropylphenylborane (tripyl-borane)7 gave organoboron main-chain polymers (scheme 3). The polymerization was... 

Hydroboration reaction of the terminal double bond of polystyrene with thexyl-borane yielded a polymer bearing one organoboron unit at the center of the polymer... 

M. Matsumi, K. Naka, and Y. Chujo, Poly(p-phenylene-borane)s, novel organoboron ir-conjugated polymers via Grignard reagent,/. Am. Chem. Soc., 120 10776-10777,1998. 

The combinahon of iridium(l)-catalyzed hydroborahon with the bulkiest borane 4,4,5,5-tetraphenyl-l,3,2-dioxaborolane (HBBzpin) allowed the selective synthesis of a series of novel stable organoboronates, in contrast to the rhodium-catalyzed version (Scheme 7.20) [42]. 

Atmospheric boron is in the form of particulates or aerosols of borides, boron oxide, borates, boranes, organoboron compounds, trihalide boron compounds, or borazines. The half-time persistence of airborne boron particles is short, usually on the order of days (USPHS 1991). 

The field of organoboron chemistry pioneered by Brown [40] also provides a wealth of excellent transformations. Consider the asymmetric reduction of carbonyl compounds by Alpine-Borane [41]. Alpine-Borane is prepared by the following sequence ... 

The reaction is called hydroboration and is a versatile synthesis of organoboron compounds. One example is the addition of diborane, B2H6, to ethene. Di-borane behaves as though it is in equilibrium with BH3 (B2H6 <= 2BH3), and addition proceeds in three stages ... 

Organoboron heterocycles containing the boron-boron bond have also been prepared by the reaction of A -lithio derivatives of alkylbis(alkylamino)-boranes with l,2-dichloro-l,2-bis (dimethylamino)diborane(4) 74) ... 

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