Dynamic kinetic resolution of a tertiary alcohol

Abstract

The first example of a dynamic kinetic resolution of a racemic tertiary alcohol is presented. By combining a lipase-catalyzed kinetic resolution and a racemization with an oxovanadium-catalyst, the ester was obtained in 77% yield and with >99% ee.

Ring-opening hydrolysis of spiro-epoxyoxindoles using a reusable sulfonic acid functionalized nitrogen rich carbon catalyst

“…The construction of tertiary alcohols bearing different carbon substituents is challenging and has a potential role in biological applications. 50,51 With this in mind, we are interested in studying the hydrolytic ring-opening of spiro-epoxyoxindoles that lead to the formation of differently substituted alcohols. We commenced our catalytic study using p -toluenesulfonic acid ( p -TSA) as a homogeneous catalyst for the hydrolysis of N -benzyl spiro-epoxyoxindole as a model substrate using dry acetonitrile at 50 °C ( Table 1 , Entry 1).…”

Expanding the Synthetic Toolbox through Metal–Enzyme Cascade Reactions

“…Despite the plethora of examples for the DKRs of secondary alcohols, the application to tertiary alcohols is still in its infancy. Remarkably, Akai, Gröger, and co-workers have recently described the use of the oxovanadium catalyst [VO­(OSiPh 3 ) 3 ] immobilized on mesoporous silica (V-MPS4) and the Candida antarctica lipase type A (CAL-A) for the performance of the first example of DKR over these highly hindered substrates . In fact, the reactivity of racemic 1-methyl-1,2,3,4-tetrahydronaphthalen-1-ol with vinyl acetate was exhaustively analyzed considering different parameters such as the catalyst type, temperature, and solvent, finding the occurrence of the DKR process.…”

Progress on the Stereoselective Synthesis of Chiral Molecules Based on Metal-Catalyzed Dynamic Kinetic Resolution of Alcohols with Lipases

“…Recently, tertiary alcohols have been reported to undergo complete and selective racemization in the presence of an acidic resin material, but no data are available about the combination with a lipase [42]. Remarkably, in 2020 Akai and Gröger found that V-MPS triggered the racemization of (S)-1,2,3,4-tetrahydronaphthalene-1-ol (25 • C, 24 h, 44%→16% ee) [43]. The co-catalyzed DKR of the tertiary alcohol in the presence of CAL-A from Candida antartica lipase A and vinyl acetate led to the desired (R)-acetate in 77% yield and excellent ee value (>99%) (Scheme 8).…”