Bench-stable imine surrogates for the one-pot and catalytic asymmetric synthesis of α-amino esters/ketones

Abstract

N,O-Bis(tert-butoxycarbonyl) hydroxylamines are readily accessible as imine surrogates, which are bench stable and could quantitatively generate the corresponding imines for in situ applications. An unpresented catalytic asymmetric method for the...

In the Pursuit of (Ald)Imine Surrogates for the Direct Asymmetric Synthesis of Non-Proteinogenic α-Amino Acids

“…In 2020, Wang and He reported an innovative approach to some bench-stable -imino ester surrogates derived from glycine 20, with nitrogen-centered leaving groups such as the N,O-Bis(Boc) hydroxylamine moiety (Scheme 14). 20…”

Enantioselective synthesis of α-amino ketones through palladium-catalyzed asymmetric arylation of α-keto imines

“… 10 In contrast, so far, the application of α-keto imines/iminium ions in catalytic asymmetric synthesis is still very few. 11 Recently, several organocatalytic asymmetric reactions of α-keto imines/iminium ions have been developed, 12 but metal-catalyzed asymmetric conversion has not yet been achieved.…”

Interrupted Polonovski Strategy for the Synthesis of Functionalized Amino Acids and Peptides

“…Hence, an interrupted Polonovski strategy looks like an attractive method to access glycine derivatives under mild conditions (Scheme B). Surprisingly, there is only one example of such a transformation: The He group used N,O -bis( tert -butoxycarbonyl) hydroxylamine methyl glycinates as imine surrogates for the asymmetric addition of diketones or diesters using a bifunctional organocatalyst . We wondered whether the interrupted Polonovski strategy could be extended to various nucleophilic heteroatoms and other carbon nucleophiles.…”

“…Surprisingly, there is only one example of such a transformation: The He group used N,O-bis(tert-butoxycarbonyl) hydroxylamine methyl glycinates as imine surrogates for the asymmetric addition of diketones or diesters using a bifunctional organocatalyst. 22 We wondered whether the interrupted Polonovski strategy could be extended to various nucleophilic heteroatoms and other carbon nucleophiles. Herein, we report a general α-functionalization of carbamateprotected hydroxylamine glycine derivatives under mild basic conditions through an interrupted Polonovski reaction (Scheme 1C).…”