Intramolecular selective stabilization through

Causes of Reversal in Tautomeric Form Selective Stabilization Through Far Intramolecular Hydrogen Bonding... 

Laser flash photolysis of phenylchlorodiazirine was used to measure the absolute rate constants for intermolecular insertion of phenylchlorocarbene into CH bonds of a variety of co-reactants. Selective stabilization of the carbene ground state by r-complexation to benzene was proposed to explain the slower insertions observed in this solvent in comparison with those in pentane. Insertion into the secondary CH bond of cyclohexane showed a primary kinetic isotope effect k ikY) of 3.8. l-Hydroxymethyl-9-fluorenylidene (79), generated by photolysis of the corresponding diazo compound, gave aldehyde (80) in benzene or acetonitrile via intramolecular H-transfer. In methanol, the major product was the ether, formed by insertion of the carbene into the MeO-H bond, and the aldehyde (80) was formed in minor amounts through H-transfer from the triplet carbene to give a triplet diradical which can relax to the enol. 

Internal templating refers to the self-selection of library members through intramolecular or intermolecular stabilizing noncovalent interactions. Intramolecular self-templating is observed when the species formed in a DCL are capable of folding upon themselves (Figure 1.2c). The library members that are best able to form favorable noncovalent interactions within themselves will be ampHfied in the library. DCC has therefore been used to study the folding of peptides, nucleotides, and synthetic polymers (Chapter 6). It can be used to direct the reversible... 

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