Axially chiral hemiaminals from nonracemic α‐amino acid derivatives (thiohydantoins): Synthesis and isomer identification
作者:Sevgi Sarigul Ozbek、Ilknur Dogan
DOI:10.1002/chir.23274
日期:2020.11
Stable, nonracemic axially chiral hemiaminals (O,N‐hemiacetals) have been synthesized stereoselectively from lithium aluminum hydride (LiAlH4) reductions of nonracemic 5‐methyl‐ and 5‐isopropyl‐3‐(o‐aryl)‐2‐thioydantoins in tetrahydrofuran (THF) at room temperature in 10 min. Predominantly S‐configured hemiaminals at C‐4 of the heterocyclic ring were produced from the S‐configured thiohydantoins at
Atroposelective Synthesis of Axially Chiral Thiohydantoin Derivatives
作者:Sevgi Sarigul、Ilknur Dogan
DOI:10.1021/acs.joc.6b00696
日期:2016.7.15
atroposelectively by the reaction of o-aryl isothiocyanates with amino acid ester salts in the presence of triethylamine (TEA). The synthesis of the nonaxially chiral derivatives, however, gave thiohydantoins racemized at C-5 of the heterocyclic ring. The micropreparatively resolved enantiomers of the nonaxially chiral derivatives from the racemic products were found to be optically stable under neutral conditions