Deuteration norbornene

Ir(Tp )(r 4-2,3-di methyl butadiene)] was investigated for selective deuteration of norbornene derivatives.78... 

Houk s model (Fig. 3 [206,207]) assiunes that the factors that are responsible for the non-planarity of the norbornene double bond intervene in the transition states of the cycloadditions of 5-cis-butadiene moieties grafted at C(2), C(3) of norbornane and 7-oxanorbornane systems. The tighter the transition states, the higher the endo face selectivity. The less synchronous the cycloaddition (e.g., with non-symmetrical dienophiles coordinated to Lewis acids), the lower the endo face preference, steric factors competing in favor of the exo mode of addition. This theory is verified for a large number of cycloadditions including those we reported for deuterated 2,3-dimethylidenebicyclo [2.2.1] heptane [208]. 

For SANS studies, a series of partially deuterated monomers (use of perdeuterocyclopentadiene for the norbornene syntheses) was synthesized. The molecular weight data of the resulting polymers with spacer length of n=4 to n=9 are... 

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