Synthesis of Axially Chiral Carboxamides via Aminocarbonylation of Aryl and Vinyl Iodides with 2,2’‐Diamino‐1,1’‐binaphthalene in the Presence of Palladium Catalysts

Noémi Pálinkás,Gábor Mikle,Antal Péter,Anita Aranyi,László Kollár

doi:10.1002/slct.202002093

Noémi Pálinkás, Gábor Mikle + Show 3 more

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https://doi.org/10.1002/slct.202002093

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Journal: ChemistrySelect	Publication Date: Sep 16, 2020
Citations: 3	License type: CC BY 4.0

Affiliation: University of Pecs, University of Szeged

Abstract

AbstractPalladium‐catalysed aminocarbonylation of iodobenzene and 1‐iodocyclohexene with both enantiomerically pure and racemic 2,2’‐diamino‐1,1’‐binaphthalene (BINAM) as N‐nucleophile was carried out. The mono‐ and dicarboxamide enantiomers possessing axial chirality were synthesised using (Sax)‐BINAM. In the possession of these reference compounds the partial chiral kinetic resolution of racemic BINAM was carried out using various optically active bidentate ligands such as (2S,4S)‐BDPP, (2S,3S)‐CHIRAPHOS and (R)‐BINAP. It was revealed by chiral HPLC measurements that up to 10 % enantiomeric excess of carboxamides can be achieved in this way. Although with low enantioselection, enantioselectve aminocarbonylation was carried out for the first time.

Highlights

A great variety of synthetic methods is available for the synthesis of carboxamides, and is discussed in details in handbooks, treatises, and even textbooks, the transition metal catalysed carbonylation reactions are among the most important ones
Some aminocarbonylations of industrial importance were published.[4]. Both iodoalkenes and N-nucleophiles possessing central element of chirality were used in aminocarbonylation, sporadic results on the same reaction involving reactants with axial chirality were published
The aminocarbonylation of iodobenzene (1) was carried out in the presence of (Sax)-BINAM in order to synthesise the enantiomers of carboxamides as reference compounds for further catalytic investigations (Scheme 1, upper reaction)

Summary

Introduction

A great variety of synthetic methods is available for the synthesis of carboxamides, and is discussed in details in handbooks, treatises, and even textbooks, the transition metal catalysed carbonylation reactions are among the most important ones. Palladium-catalysed aminocarbonylation,[1] enabling the direct synthesis of carboxamides from available substrates, provided a real breakthrough in the synthesis of otherwise hardly available carboxamides Using this methodology, aryl and alkenyl halides (especially iodides and bromides) or the corresponding triflates, their synthetic surrogates, can be transformed to carboxamides.[2,3] Some aminocarbonylations of industrial importance were published.[4]. Aryl and alkenyl halides (especially iodides and bromides) or the corresponding triflates, their synthetic surrogates, can be transformed to carboxamides.[2,3] Some aminocarbonylations of industrial importance were published.[4] Both iodoalkenes and N-nucleophiles possessing central element of chirality were used in aminocarbonylation, sporadic results on the same reaction involving reactants with axial chirality were published.

Results and Discussion

Conclusions

Conflict of Interest