85153-64-6Relevant academic research and scientific papers
Use of the Nonionic Superbase P(MeNCH2CH2)3N in the Selective Monoalkylation of Active-Methylene Compounds
Arumugam, Subramaniam,McLeod, Dale,Verkade, John G.
, p. 3677 - 3679 (1998)
The symmetric active-methylene compounds CH2(CO2Et)2 and CH2[C(O)Me]2 are selectively monoalkylated in the presence of 1.1 equiv of a variety of alkyl halides and 1 equiv of the nonionic Superbase P(MeNCH2CH2)2N in 85-98% yields in 30 min at room temperature. The unsymmetrical active-methylene compound EtO2CCH2C(O)Me is selectively monoalkylated under the same conditions, except for the temperature, which is 0 °C, in 59-88% yields. The observation of selective C- rather than O-alkylation is rationalized in terms of the formation of an enolate whose negatively charged oxygen is sterically protected by a nearby HP(MeNCH2CH2)2N+ counterion in a tight ion pair.
