title: Predictable stereoselective and chemoselective hydroxylations and epoxidations with P450 3A4.
abstract: Enantioselective hydroxylation of one specific methylene in the presence of many similar groups is debatably the most challenging chemical transformation. Although chemists have recently made progress toward the hydroxylation of inactivated C-H bonds, enzymes such as P450s (CYPs) remain unsurpassed in specificity and scope. The substrate promiscuity of many P450s is desirable for synthetic applications; however, the inability to predict the products of these enzymatic reactions is impeding advancement. We demonstrate here the utility of a chemical auxiliary to control the selectivity of CYP3A4 reactions. When linked to substrates, inexpensive, achiral theobromine directs the reaction to produce hydroxylation or epoxidation at the fourth carbon from the auxiliary with pro-R facial selectivity. This strategy provides a versatile yet controllable system for regio-, chemo-, and stereoselective oxidations at inactivated C-H bonds and demonstrates the utility of chemical auxiliaries to mediate the activity of highly promiscuous enzymes.
authors.affiliation: Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada H3A 2K6.
authors.forename: Aaron T
authors.initials: AT
authors.lastname: Larsen
authors.forename: Erin M
authors.initials: EM
authors.lastname: May
authors.forename: Karine
authors.initials: K
authors.lastname: Auclair
mesh_terms: D002851:Chromatography, High Pressure Liquid; D051544:Cytochrome P-450 CYP3A / Q000737:chemistry / Q000378:metabolism*; D004852:Epoxy Compounds / Q000378:metabolism*; D006900:Hydroxylation; D008958:Models, Molecular; D013237:Stereoisomerism
chemical_list: D004852:Epoxy Compounds; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human