Posts Tagged ‘Superbase’

What is the approach trajectory of enhanced (super?) nucleophiles towards a carbonyl group?

Wednesday, May 11th, 2016

I have previously commented on the Bürgi–Dunitz angle, this being the preferred approach trajectory of a nucleophile towards the electrophilic carbon of a carbonyl group. Some special types of nucleophile such as hydrazines (R2N-NR2) are supposed to have enhanced reactivity[1] due to what might be described as buttressing of adjacent lone pairs. Here I focus in on how this might manifest by performing searches of the Cambridge structural database for intermolecular (non-bonded) interactions between X-Y nucleophiles (X,Y= N,O,S) and carbonyl compounds OC(NM)2.

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References

  1. G. Klopman, K. Tsuda, J. Louis, and R. Davis, "Supernucleophiles—I", Tetrahedron, vol. 26, pp. 4549-4554, 1970. http://dx.doi.org/10.1016/S0040-4020(01)93101-1