TY - JOUR
T1 - Biocatalytic Generation of o-Quinone Imines in the Synthesis of 1,4-Benzoxazines and Its Comparative Green Chemistry Metrics
AU - Tehami, Maryam
AU - Imam, Hasan Tanvir
AU - Abdullah, Iskandar
AU - Hosford, Joseph
AU - Wong, Xiao Juie
AU - Rahman, Noorsaadah Abd
AU - Wong, Lu Shin
PY - 2024/2/19
Y1 - 2024/2/19
N2 - 1,4-Benzoxazines are important motifs in many pharmaceuticals and can be formed by a reaction sequence involving the oxidation of o-aminophenols to their corresponding quinone imine followed by an in situ inverse electron demand Diels-Alder (IEDDA) cycloaddition with a suitable dienophile. Reported herein is the development of a reaction sequence that employs horseradish peroxidase to catalyze the oxidation of the aminophenols prior to the IEDDA as a more sustainable alternative to the use of conventional stoichiometric oxidants. The synthesis of 10 example benzoxazines is demonstrated in this “one-pot, two-step” procedure with yields between 42% and 92%. The green chemistry metrics, including the E-factor and generalized reaction mass efficiency, for this biocatalytic reaction were compared against the conventional chemical approach. It was found that the reported biocatalytic route was approximately twice as green by these measures.
AB - 1,4-Benzoxazines are important motifs in many pharmaceuticals and can be formed by a reaction sequence involving the oxidation of o-aminophenols to their corresponding quinone imine followed by an in situ inverse electron demand Diels-Alder (IEDDA) cycloaddition with a suitable dienophile. Reported herein is the development of a reaction sequence that employs horseradish peroxidase to catalyze the oxidation of the aminophenols prior to the IEDDA as a more sustainable alternative to the use of conventional stoichiometric oxidants. The synthesis of 10 example benzoxazines is demonstrated in this “one-pot, two-step” procedure with yields between 42% and 92%. The green chemistry metrics, including the E-factor and generalized reaction mass efficiency, for this biocatalytic reaction were compared against the conventional chemical approach. It was found that the reported biocatalytic route was approximately twice as green by these measures.
KW - Diels-Alder reaction
KW - E-factor
KW - horseradish peroxidase
KW - inverse electron demand Diels-Alder
KW - peroxidase
KW - reaction mass efficiency
KW - tandem reaction
UR - http://www.scopus.com/inward/record.url?scp=85184831324&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/f8d69371-f205-32d1-8a5c-ceead76ce3e1/
U2 - 10.1021/acssuschemeng.3c06758
DO - 10.1021/acssuschemeng.3c06758
M3 - Article
C2 - 38389905
SN - 2168-0485
VL - 12
SP - 2678
EP - 2685
JO - ACS Sustainable Chemistry & Engineering
JF - ACS Sustainable Chemistry & Engineering
IS - 7
ER -