Horseradish peroxidase: An effective but unselective biocatalyst for biaryl synthesis

Recent advances in asymmetric oxidative coupling of 2‐naphthol and its derivatives

“…In 1997, Sridhar et al described the first application of enzyme catalysis, using horseradish peroxidase (HRP), a commercially available metalloporphyrin enzyme, for enantioselective synthesis of (R)-BINOL 1 derivatives with moderate ee. 73 Contrary to this report, Schreier and coworkers 74 published that the HRP catalyzed oxidative dimerization of 2 leading to BINOL 1 in 35% chemical yield with < 5% ee, which indicated that the HRP is an effective but unenantioselective biocatalyst. Recently, Takemoto et al 75 investigated Camelliasinensis cell culture catalyzed enantioselective oxidative coupling of 27.…”

Preparation and Enantiomeric Excess Determination of Optically Active BINOL and BINOL Derivatives

“…For example, horseradish peroxidase was reported to catalyze the oxidation of 2-naphthol by hydrogen peroxide to give (R)-BINOL in 75% yield and 52% ee [26]. These results, however, have been called into question when attempts to repeat them failed to detect any enantiomeric excess in the BINOL produced [27].…”

“…For example, treatment of phosphoryl chloride (26) (prepared from BINOL and POCl 3 ) with (S)-α-methylbenzylamine provides a pair of diastereomeric phosphoramidates (27), which can be separated by just one recrystallization from ethanol (Fig. (14)).…”

“…It was noted in the reaction above that one diastereomer of (27) formed faster than the other, so the possibility of doing a kinetic resolution was investigated. Of several amines examined, it was found that hindered amine (28) gave the best results.…”

Oxidative Aryl‐Coupling Reactions in Synthesis

“…Horseradish peroxidase (HRP) as a biocatalyst has been separately studied by Sridhar and Schreier [140,141]. Unfortunately, contrasting results were reported.…”