Multiple bonding boron-carbon

This review will restrict itself to boron-carbon multiple bonding in carbon-rich systems, as encountered in organic chemistry, and leave the clusters of carboranes rich in boron to the proper purview of the inorganic chemist. Insofar as such three-dimensional clusters are considered at all in these review, interest will focus on the carbon-rich carboranes and the effect of ring size and substituents, both on boron and carbon, in determining the point of equilibrium between the cyclic organoborane and the isomeric carborane cluster. A typical significant example would be the potential interconversion of the l,4-dibora-2,5-cyclohexadiene system (7) and the 2,3,4,5-tetracarbahexaborane(6) system (8) as a function of substituents R (Eq. 2). 

Other multiple bonds, eg,, —C=N, —N=N—, also undergo the addition. However, those reactions not involving boron—carbon bond... 

Eisch, John J., Boron-Carbon Multiple Bonds. 39 355... 

Eisch, John J Boron-Carbon Multiple Bonds. 

II. Boron-Carbon Multiple Bonding in Open-Chain Unsaturated Organo-... 

IV. Unsolved Problems in Boron-Carbon Multiple Bonding and Remaining... 

The question of multiple bonding between boron and carbon when there is no cyclic aromatic character to be gained, as for example in vinylboranes (structures 5a and 5b), is more difficult to decide. 

BORON-CARBON MULTIPLE BONDING IN OPEN-CHAIN UNSATURATED ORGANOBORANES... 

The intramolecular rearrangement of allylic boranes (Eq. 5) clearly involves a multiple boron-carbon bond in the transition state (45), as the boron 2pz-orbital interacts with the 7r-bonding MO. 

UNSOLVED PROBLEMS IN BORON-CARBON MULTIPLE BONDING AND REMAINING CHALLENGES... 

Although the term hydroboration is most commonly employed2-3 16 to denote the addition of a boron-hydrogen linkage to carbon-carbon multiple bonds, it has also been used for the two-step oxidative process to distinguish it from the process of reduction involving H-B addition and protonolysis. 18... 

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