American Chemical Society
ja8050487_si_001.pdf (2.36 MB)

Stereoselective Synthesis of cis- or trans-3,5-Disubstituted Pyrazolidines via Pd-Catalyzed Carboamination Reactions: Use of Allylic Strain to Control Product Stereochemistry Through N-Substituent Manipulation

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journal contribution
posted on 2008-10-01, 00:00 authored by Natalie C. Giampietro, John P. Wolfe
The stereoselective synthesis of either trans- or cis-3,5-disubstituted pyrazolidines is accomplished via Pd-catalyzed carboamination reactions of unsaturated hydrazine derivatives. The products are obtained in good yield with up to >20:1 diastereoselectivity. Stereocontrol is achieved by modulating the degree of allylic strain in the transition state for syn-aminopalladation through a simple modification of the substrate N2-substituent. The pyrazolidine products can be further transformed to 3,5-disubstituted pyrazolines via deprotection/oxidation, or to substituted 1,3-diamines via N−N bond cleavage.