Catalytic Enantioselective Synthesis of α‐(Benzylamino)cyclobutanones

Abstract

An organocatalytic enantioselective synthesis of α‐(benzylamino)cyclobutanones has been achieved by employing a tandem condensation/intramolecular rearrangement/proton transfer reaction and starting from racemic α‐hydroxycyclobutanone and a selection of benzylamines. This reaction sequence afforded the products in good to high yields with moderate to high enantioselectivities.

Catalytic asymmetric synthesis of N-substituted tetrahydroquinoxalines via regioselective Heyns rearrangement and stereoselective transfer hydrogenation in one pot

“…Therefore, this rearrangement appears to be highly underrated as a useful method for synthetic chemists. 9 Due to the significance of the reaction as well as the importance of the corresponding products, our group has paid much attention to its application. 10 Recently, we investigated the production and application of the in situ formed α-amino aldehyde intermediate and synthesized different N-heterocycles by using different types of nucleophiles.…”

Diastereo- and Enantioselective CuH-Catalyzed Hydroamination of Strained Trisubstituted Alkenes

“…Thus, considerable effort has been expended to develop methods for the stereoselective construction of these structural units. Currently, most synthetic approaches to enantioenriched cyclobutylamines are based on [2 + 2] cycloadditions and the Amadori–Heyns rearrangement . Among these methods, few are catalytic and effective in an intermolecular context. − , In contrast, for the catalytic, enantioselective synthesis of cyclopropylamines, a number of elegant methods have been developed .…”

“…Currently, most synthetic approaches to enantioenriched cyclobutylamines are based on [2 + 2] cycloadditions and the Amadori–Heyns rearrangement . Among these methods, few are catalytic and effective in an intermolecular context. − , In contrast, for the catalytic, enantioselective synthesis of cyclopropylamines, a number of elegant methods have been developed . The most well-known processes include intramolecular C–H activation of prochiral aminocyclopropanes, cyclopropanation of vinylcarbamates, carboamination of cyclopropenes, and rare-earth metal-catalyzed hydroamination of cyclopropenes .…”

Investigation and Application of Amphoteric α-Amino Aldehyde: An in Situ Generated Species Based on Heyns Rearrangement

“…Therefore, this rearrangement appears to be highly underrated as a useful method for synthetic chemists . Recently, this rearrangement was extended to the synthesis of α-amino ketones with α-hydroxy ketones and a suitable amine as starting materials …”

“…In general, the reaction proceeded smoothly and afforded the corresponding quinoxalines with excellent yield (85–95%) ( 7b – f , Scheme ). Strikingly, 2,3-disubstituted quinoxalines were obtained using the corresponding α-hydroxy ketone as substrates ( 7g , h , Scheme ), in which transient α-amino ketone might be involved …”