22520-39-4Relevant articles and documents
Origin of α-Hydroxy Ketones in the Osmium Tetroxide-Catalyzed Asymmetric Dihydroxylation of Alkenes
Lohray, Braj B.,Bhushan, Vidya,Kumar, R. Krishna
, p. 1375 - 1380 (1994)
The origin and the mechanism of formation of α-hydroxy ketones in the osmium tetroxide-catalyzed asymmetric cis-dihydroxylation (ADH) of alkenes in the presence of tert-butyl hydroperoxide is described.The formation of α-hydroxy ketones has been established to proceed through either the hydration of monooxobisglycolate ester 2 followed by oxidation with tert-butyl hydroperoxide (TBHP) or by acid-catalyzed addition of TBHP on the intermediate bisglycolate ester 2.On the basis of the mechanistic insight, it has been possible to shut down the formation of α-hydroxy ketones and other side products in the ADH reaction, even when TBHP is used as an oxygen source.It is possible to prepare α-hydroxy ketones in good yields but the optical purity of ketols has been found to be very low, which not only shed significant light on the mechanism of their formation, but also delineated the improbability of syntesizing them in optically active forms by ADH reaction of alkenes.
Assessing the stereoselectivity of: Serratia marcescens CECT 977 2,3-butanediol dehydrogenase
Médici, Rosario,Stammes, Hanna,Kwakernaak, Stender,Otten, Linda G.,Hanefeld, Ulf
, p. 1831 - 1837 (2017/07/15)
α-Hydroxy ketones and vicinal diols constitute well-known building blocks in organic synthesis. Here we describe one enzyme that enables the enantioselective synthesis of both building blocks starting from diketones. The enzyme 2,3-butanediol dehydrogenase (BudC) from S. marcescens CECT 977 belongs to the NADH-dependent metal-independent short-chain dehydrogenases/reductases family (SDR) and catalyses the selective asymmetric reductions of prochiral α-diketones to the corresponding α-hydroxy ketones and diols. BudC is highly active towards structurally diverse diketones in combination with nicotinamide cofactor regeneration systems. Aliphatic diketones, cyclic diketones and alkyl phenyl diketones are well accepted, whereas their derivatives possessing two bulky groups are not converted. In the reverse reaction vicinal diols are preferred over other substrates with hydroxy/keto groups in non-vicinal positions.
Amine Catalysis for the Organocatalytic Diboration of Challenging Alkenes
Farre, Albert,Soares, Kaline,Briggs, Rachel A.,Balanta, Angelica,Benoit, David M.,Bonet, Amadeu
, p. 17552 - 17556 (2016/11/28)
The generation of in situ sp2–sp3diboron adducts has revolutionised the synthesis of organoboranes. Organocatalytic diboration reactions have represented a milestone in terms of unpredictable reactivity of these adducts. However, current methodologies have limitations in terms of substrate scope, selectivity and functional group tolerance. Here a new methodology based on the use of simple amines as catalyst is reported. This methodology provides a completely selective transformation overcoming current substrate scope and functional/protecting group limitations. Mechanistic studies have been included in this report.
