Related Experiment Video
Updated: Jan 3, 2026

Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine
Published on: June 13, 2022
Phosphoramidates as Steering Elements for Highly Selective Access to Complementary Imidazo[1,2-a]pyrimidine Isomers
Nicholas A White1, Kyle Clagg1, Lauren E Sirois1
1Department of Small Molecule Process Chemistry , Genentech, Inc. , 1 DNA Way , South San Francisco , California 94080 , United States.
Abstract:
We report that selective N-phosphorylation of aminoimidazoles results in a key steering element that controls isomeric selectivity in the condensation of β-ethoxy acrylamides and aminoimidazoles to furnish imidazo[1,2-a]pyrimidines. We identified conditions that provide highly selective (99:1) phosphorylation at the endo- or exocyclic nitrogen. Either the 2-amino or 4-amino isomer of the (benzo)imidazo[1,2-a]pyrimidine products could be isolated in 64-95% yield. Mass spectrometric analysis and computational studies give insight into the mechanism of this exceptionally selective transformation.
Related Concept Videos
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Preparation of 1° Amines: Gabriel Synthesis
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Basicity of Heterocyclic Aromatic Amines
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview
Biosynthesis of Nucleic Acids
Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...

