20409-89-6Relevant academic research and scientific papers
A convenient synthesis of substituted pyrazolidines and azaproline derivatives through highly regio- and diastereoselective reduction of 2-pyrazolines
De Los Santos, Jesus M.,Lopez, Yago,Aparicio, Domitila,Palacios, Francisco
, p. 550 - 557 (2008/09/17)
(Chemical Equation Presented) The synthesis of substituted N-acetyl- and N-aroyl-2-pyrazolines via intramolecular Michael addition of α,β-unsaturated hydrazones generated through olefination of phosphinyl and phosphonyl hydrazones with carbonyl compounds is reported. The regioselective reduction of the C-N double bond in these 2-pyrazolines using Superhydride (Et3BHLi) gives pirazolidine derivatives with excellent levels of cis-diastereoselectivity. These 2-pyrazolines can also be obtained in one-pot reaction from allenes, hydrazides, and aldehydes; and pyrazolidines, after reduction, from allenes, hydrazides, and aldehydes. This synthetic route was developed to provide a new approach to substituted azaproline derivatives in a diastereoselective fashion.
