Catalytic Oxidations in a Bio-Based Economy

Abstract

The role of bio-and chemo-catalytic aerobic oxidations in the production of commodity chemicals in a bio-refinery is reviewed. The situation is fundamentally different to that in a petrochemicals refinery where the feedstocks are gaseous or liquid hydrocarbons that are oxidized at elevated temperatures in the vapor or liquid phase under solvent-free conditions. In contrast, the feedstocks in a biorefinery are carbohydrates that are water soluble solids and their conversion will largely involve aerobic oxidations of hydroxyl functional groups in water as the solvent under relatively mild conditions of temperature and pressure. This will require the development and use of cost-effective and environmentally attractive processes using both chemo-and biocatalytic methods for alcohols and polyols.

Development of Continuous Flow Systems to Access Secondary Amines Through Previously Incompatible Biocatalytic Cascades**

“…Biocatalytic oxidations are fundamental in transitioning to a bio‐based economy, in particular the use of oxidases which carry out selective oxidation using molecular oxygen as the sole oxidant. [ 18 , 19 ] To overcome potential limitations of oxygen concentration, a previously described multipoint injection reactor (MPIR) was employed; it was shown to greatly improve the productivity of oxidase biocatalysts by negating low aqueous oxygen availability through in situ biocatalytic generation from hydrogen peroxide (Table 1 ). [ 20 , 21 , 22 ] An engineered choline oxidase (AcCO 6 ) was initially chosen as an ideal biocatalyst to test in the MPIR due to its broad substrate scope and as it has been applied in biocatalytic cascades.…”

“…As aldehydes are versatile yet unstable intermediates, it was thought a continuous flow system that generated this group in situ at high concentrations could allow for a range of subsequent enzymatic modifications. Biocatalytic oxidations are fundamental in transitioning to a bio‐based economy, in particular the use of oxidases which carry out selective oxidation using molecular oxygen as the sole oxidant [18, 19] . To overcome potential limitations of oxygen concentration, a previously described multipoint injection reactor (MPIR) was employed; it was shown to greatly improve the productivity of oxidase biocatalysts by negating low aqueous oxygen availability through in situ biocatalytic generation from hydrogen peroxide (Table 1).…”

Development of Continuous Flow Systems to Access Secondary Amines Through Previously Incompatible Biocatalytic Cascades**

“…Ther eaction cascades described here started with the generation of aldehydes from stable and commercially available alcohols.A sa ldehydes are versatile yet unstable intermediates,i tw as thought ac ontinuous flow system that generated this group in situ at high concentrations could allow for ar ange of subsequent enzymatic modifications.B iocatalytic oxidations are fundamental in transitioning to ab iobased economy,inp articular the use of oxidases which carry out selective oxidation using molecular oxygen as the sole oxidant. [18,19] To overcome potential limitations of oxygen concentration, ap reviously described multipoint injection reactor (MPIR) was employed;i tw as shown to greatly improve the productivity of oxidase biocatalysts by negating low aqueous oxygen availability through in situ biocatalytic generation from hydrogen peroxide (Table 1). [20][21][22] An engineered choline oxidase (AcCO 6 )w as initially chosen as an ideal biocatalyst to test in the MPIR due to its broad substrate scope and as it has been applied in biocatalytic cascades.…”

Production of High Value Amine Intermediates via Biocatalytic Cascades in Continuous Flow

“…Biocatalytic oxidations are fundamental in transitioning to a bio-based economy, in particular the use of oxidases which carry out selective oxidation using molecular oxygen as the sole oxidant. 18,19 To overcome potential limitations of oxygen concentration, a previously described multipoint injection reactor (MPIR) was employed; it was shown to greatly improve the productivity of oxidase biocatalysts by negating low aqueous oxygen availability through in situ biocatalytic generation from hydrogen peroxide (Table 1). [20][21][22] An engineered choline oxidase (AcCO6) was initially chosen as an ideal biocatalyst to test in the MPIR due to its broad substrate scope and as it has been applied in biocatalytic cascades.…”