220333-15-3Relevant academic research and scientific papers
Asymmetric synthesis of tertiary α -hydroxyketones by enantioselective decarboxylative chlorination and subsequent nucleophilic substitution
Kam, Mei Kee,Sugiyama, Akira,Kawanishi, Ryouta,Shibatomi, Kazutaka
, (2020)
Chiral tertiary α-hydroxyketones were synthesized with high enantiopurity by asymmetric decarboxylative chlorination and subsequent nucleophilic substitution. We recently reported the asymmetric decarboxylative chlorination of β-ketocarboxylic acids in the presence of a chiral primary amine catalyst to obtain α-chloroketones with high enantiopurity. Here, we found that nucleophilic substitution of the resulting α-chloroketones with tetrabutylammonium hydroxide yielded the corresponding α-hydroxyketones without loss of enantiopurity. The reaction proceeded smoothly even at a tertiary carbon. The proposed method would be useful for the preparation of chiral tertiary alcohols.
Direct Asymmetric α-Hydroxylation of Cyclic α-Branched Ketones through Enol Catalysis
Shevchenko, Grigory A.,Pupo, Gabriele,List, Benjamin
supporting information, p. 49 - 53 (2019/01/04)
Enantiopure α-hydroxy carbonyl compounds are common scaffolds in natural products and pharmaceuticals. Although indirect approaches towards their synthesis are known, direct asymmetric methodologies are scarce. Herein, we report the first direct asymmetric α-hydroxylation of α-branched ketones through enol catalysis, enabling a facile access to valuable α-keto tertiary alcohols. The transformation, characterized by the use of nitrosobenzene as the oxidant and a new chiral phosphoric acid as the catalyst, delivers a good scope and excellent enantioselectivities.
Diastereoselective α-iminoamine rearrangement: Asymmetric synthesis of (R)-(-)- and (S)-(+)-2-benzyl-2-hydroxy-cyclohexanone
Bisel, Philippe,Lauktien, Gerhard,Weckert, Edgar,Frahm, August W.
, p. 4027 - 4034 (2007/10/03)
A convenient asymmetric synthesis of both (R)-(-)- and (S)-(+)-2- benzyl-2-hydroxycyclohexanones starting from racemic 2- benzyloxycyclohexanone and the chiral auxiliary 1-phenylethylamine is reported. The route involves a [1,3]-sigmatropic shift and a ne
