Iron complexes for enantioselective cis dihydroxylation of alkenes
AssigneesThe University of Hong Kong, Laboratory for Synthetic Chemistry and Chemical Biology Limited
InventorsChi Ming Che, Tingting Wang
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Abstract
Methods for asymmetric cis-dihydroxylation (“AD”) of styrenes and conjugated dienes to produce cis-diols of styrene and conjugated diene or tetraols of conjugated diene with high yield (i.e., a yield ≥30%) and high enantioselectivity (i.e., an enantiometric excess ≥60%) are disclosed. The method uses an iron-based catalyst, such as one or more Fe(II) complexes, as the catalyst. The method generally includes: (i) maintaining a reaction mixture at a temperature for a period of time sufficient to form a product, where the reaction mixture contains a styrene or conjugated diene, one or more iron-based catalyst(s), an oxidant, and a solvent, and where the product contains a cis-diol or tetraol.
Claims25
An iron-based catalyst having the structure of:
- wherein:
- (a) L1 is a bond or
- R16, R16′, R17, and R17′ are independently a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, or a substituted or unsubstituted cyclic group, or R16 and R16′ and/or R17 and R17′ form a substituted or unsubstituted aryl, a substituted or unsubstituted polyaryl, or a substituted or unsubstituted cyclic group, and p is an integer from 1 to 10;
- (b) R18, R23, R24, R18′, R23′, and R24′ are independently a hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted aryl, a substituted or unsubstituted alkylaryl, or a substituted or unsubstituted polyaryl;
- (c) R19 is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted aryl, a substituted or unsubstituted alkylaryl, or a substituted or unsubstituted polyaryl;
- (d) R22, R22′, and R31—R34 are independently a hydrogen, a substituted or unsubstituted alkyl, a halogen, an amino, or an alkoxyl;
- (e) R25 and R25′ are independently a leaving group;
- and
- (f) the substituents are independently a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted cyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted polyaryl, a substituted or unsubstituted polyheteroaryl, a substituted or unsubstituted aralkyl, a carbonyl, a halide, a hydroxyl, a phenoxy, an aroxy, an alkylthio, a phenylthio, an arylthio, a cyano, an isocyano, an alkoxyl, a nitro, an carboxyl, an amino, an amido, an oxo, a silyl, a sulfinyl, a sulfonyl, a sulfonic acid, a phosphonium, a phosphanyl, a phosphoryl, a phosphonyl, or a thiol, or a combination thereof.
Dependencies are inferred from the claim text.