Comparative deuterated, synthesis

The DPE reduction is used as a test reaction to characterize the materials and optimize the preparation conditions of the catalyst. Since hydroaluminations can also be used for the synthesis of carboxylic acids, deuterated products, or vinyl halides via quenching with CO2, D2O or Br2 [44], the method is also a valuable organic synthesis tool. However, as compared with molecular catalysts like Cp2TiCl2 that are known to catalyze hydroaluminations [44], the titanium nitride materials described here are solid catalysts and can be separated by centrifugation. Moreover, they can be reused several times, which is an advantage as compared to molecular catalysts. 

The synthesis, normal mode analysis and the comparison of experimental and calculated VCD spectra report Malon et al. (1992) on dideuteriobutyrolactone. For the calculations they use the 6-3IG basis set. The spectra of Oxiran and its deuterated analogues have been calculated by Duller and Rauk (1989) and compared to the results of unpublished measurements of Spenzer et al. 

Most alkyl carbanions undergo facile pyramidal inversion. Cyclopropyl anions are an exception, presumably because the transition state, with a planar trigonal carbon, is more strained than the ground state. The configurational stability of cyclopropyl anions is of value in the synthesis of deuterated cyclopropanes by the Haller-Bauer reaction (see Section II.B). An interesting dilemma arises when a cyclopropyl anion is stabilized by a n-electron acceptor substituent such as a nitrile or an ester. Will the anion then retain its pyramidal equilibrium geometry for the strain reasons alluded to above, or will it become planar in order to maximize overlap of the filled orbital on carbon with the n orbital of the substituent Walborsky and coworkers addressed this question in a series of experiments in which rates of H/D exchange and racemization were compared for an optically active cyclopropane exposed to a base in a deuterated hydroxylic solvent. The outcome can be illustrated with the particular example of 1,1-diphenylcyclopropane-2-... 

In a more recent study, a series of (d-PS)(PI)2 stars, where d-PS is deuterated PS, was prepared by the same technique.93 No difference was obseved by using the deuterated arm compared to the PS(PI)2 stars. A similar study concerning the synthesis of (d-PBd)-(PBd)2 stars containing a deuterated PBd arm was also reported.94 Both kinds of arms have almost the same molecular weight, and consequently, the only difference was that one of them was labeled with deuterium. 

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