Dihydrogen Activation by Frustrated Lewis Pairs FLPs

C4H9Li - -CH2=CH-CH=CH2 C4H9-CH2-CH=CH-CH2Li Using arrow pushing, show how the polymers might now arise. 

6 DIHYDROGEN ACTIVATION BY FRUSTRATED LEWIS PAIRS (FLPs) 

Recall from Section 1.9 that the Lewis acid and base in a frustrated pair are too bulky or otherwise sterically constrained to bond with each other but the cleft between them acts like an enzyme active site and promotes remarkable chemical reactions, perhaps none more so than the activation of dihydrogen at or below room temperature. Two representative reactions mediated by P,B-based FLPs are as follows  

Observe that each of these reactions accomplishes a net heterolytic cleavage of an H2 molecule, an incredibly weak acid (pAT = 42), with the P picking up a proton and the B a hydride. How might this occur Neither a naked proton nor a naked hydride anion is plausible as an intermediate. A reaction path in which both the P and the B act in concert to break the H-H bond heterolytically is envisioned below, even though explicit experimental evidence for such a pathway is still lacking  

THE s-BLOCK ELEMENTS ALKAU AND ALKAUNE EARTH METALS 

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