Verkade’s superbase

Kovacevic, B., Baric, D. and Maksic, Z.B. (2004) Basicity of exceedingly strong non-ionic bases in acetonitrile - Verkade s superbase and some related phosphazenes. New Journal of Chemistry, 28, 284-288. 

Dimitrov-Raytchev P, Martinez A, Gomitzka H, Dutasta J-P (2011) Encaging the verkade s superbases thermodynamic and kinetic consequences. J Am Chem Soc 133 2157-2159... 

The first hybrid cage complex of hemicrypto-phanophosphatrane 218 with a superbasic center (so-called Verkade s superbase ) has been synthesized in [152] by Scheme 2.137. This complex contains one encapsulated dichloromethane molecule, which forms supramolecular bonds with... 

Other Phosphorus Containing Superbases Verkade s Proazaphosphatranes 37... 

Other phosphorus containing superbases are phosphines and phosphorus yhdes. The most detailed studied class is Verkade s proazaphosphatranes (cyclic azaphosphines). Because of the extraordinary basicity and relatively weak nucleophilicity of nonionic proazaphosphatranes, they have been found to be efficient catalysts and promoters for many reactions... 

One drawback of the use of weak bases as in situ promoters for the Schollkopf oxazole synthesis is the long time typieally required to drive such reactions to completion. For example, the condensation of methyl isocyanoacetate (14) and 3,4,5-trimethoxybenzoyl chloride (19) in the presence of DBU provides only an 8% yield of oxazole 21 after 2 h at ambient temperature. This limitation can be overcome by employing Verkade s prophosphatrane superbase (20), which, in the case of the reaction of 14 and 19, results in near-quantitative formation... 

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