The RuO₄-catalysed dihydroxylation, ketohydroxylation and mono oxidation—novel oxidation reactions for the synthesis of diols and α-hydroxy ketones

Abstract

Alpha-hydroxy ketones are versatile intermediates for the synthesis of complex molecular architectures and subunits of a variety of natural products. Different approaches towards the synthesis of this important functional group combination have been elaborated. The present article summarises our research on the field of RuO4-catalysed oxidations of alkenes that resulted in the development of the first RuO4-catalysed ketohydroxylation of olefins. Mechanistic investigations of both dihydroxylation and ketohydroxylation led to the discovery of the first regioselective catalytic mono oxidation of vic-diols, which was applied in a two-step sequence of asymmetric dihydroxylation and regioselective mono oxidation to furnish enantiopure alpha-hydroxy ketones with both predictable regioselectivity and absolute configuration.

Fe(PyTACN)‐Catalyzed cis‐Dihydroxylation of Olefins with Hydrogen Peroxide

“…Notably, olefins constitute convenient feedstocks because of their readily availability from petroleum resources. Methodologies that employ catalytic amounts of OsO 4 in combination with sacrificial oxidants have been successfully developed, [5] and less toxic Ru [6][7][8][9][10][11][12] and Pd [13][14][15][16][17][18][19] catalyst-based methods have been studied, but obviously the most attractive solution will be to discover heavy-metal free reactions. Particularly reliable in terms of yields and selectivity are methodologies that rely on the latter metal.…”

High‐Yielding Diastereoselective syn‐Dihydroxylation of Protected HBO: An Access to D‐(+)‐Ribono‐1,4‐lactone and 5‐O‐Protected Analogues

“…Nevertheless, under such conditions, no dihydroxylation was observed. Ruthenium-catalyzed syn-dihydroxylation using an in situ generation of the oxidant species RuO 4 [28] (RuCl 3 ·5H 2 O, NaIO 4 , CeCl 3 , CH 3 CN-AcOEt-water (3:3:1)) was also investigated ( Table 1, entries 2, 6 and 10). Under these conditions, HBO-TBDMS-2OH, HBO-TBDPS-2OH and HBO-Bn-2OH were obtained in 60, 62 and 60 % yields, respectively, comparable to that obtained with KMnO 4 /dicyclohexano-18-crown-6 ether.…”

Recent Developments in Metal‐Catalyzed Dihydroxylation of Alkenes

“…With this protocol, the catalyst loading can be reduced to as low as 0.5 mol% and the short reaction time (seconds or minutes) is maintained (Scheme 1.20). In the course of mechanistic studies, a novel method for ketohydroxylation was also developed [62].…”