An efficient transition-metal-free route to oligo-$\alpha $-pyridylamines via fluoroarenes
The new polynucleating tripodal proligand $\text{H}_6\text{tren(dpa)}_3$, containing thirteen nitrogen donors of four different types, was designed, synthesized, and isolated in good yield (${\sim }$60%) via a transition-metal-free triple N-arylation of $\text{H}_6$tren with HXdpa (X $=$ Br or F), u...
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Main Authors: | , , , |
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Format: | Article |
Language: | English |
Published: |
Académie des sciences
2023-03-01
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Series: | Comptes Rendus. Chimie |
Subjects: | |
Online Access: | https://comptes-rendus.academie-sciences.fr/chimie/articles/10.5802/crchim.223/ |
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Summary: | The new polynucleating tripodal proligand $\text{H}_6\text{tren(dpa)}_3$, containing thirteen nitrogen donors of four different types, was designed, synthesized, and isolated in good yield (${\sim }$60%) via a transition-metal-free triple N-arylation of $\text{H}_6$tren with HXdpa (X $=$ Br or F), using $\text{K}_2\text{CO}_3$ or $\text{Cs}_2\text{CO}_3$ as a base ($\text{H}_6$tren $=$ tris(2-aminoethyl)amine, HXdpa $=$ 6-halogeno-$N$-(pyridin-2-yl)pyridin-2-amine). HFdpa was prepared with excellent yield (90–92%) by reaction of 2,6-difluoropyridine with 2-aminopyridine in LiH/toluene/pyridine and was found more reactive than HBrdpa, affording higher conversion and higher yield. Use of $\text{Cs}_2\text{CO}_3$ turned out to be essential for achieving high regioselectivity and eliminating overarylation almost completely. |
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ISSN: | 1878-1543 |