Enantioselective aerobic oxidation of α-hydroxy-ketones catalyzed by oxidovanadium(V) methoxides bearing chiral, N-salicylidene-tert-butylglycinates.
Chiral oxidovanadium(V) methoxides prepared from 3,5-disubstituted-N-salicylidene-l-tert-butylglycines and vanadyl sulfate in air-saturated MeOH serve as highly enantioselective catalysts for asymmetric aerobic oxidations and kinetic resolution of alkyl, aryl, and heteroaryl α-hydroxy-ketones with differed α-substituents at ambient temperature in toluene or TBME (tert-butyl methyl ether). The best scenarios involve the use of complexes which bear the tridendate templates derived from 3,5-diphenyl- or 3-o-biphenyl-5-nitro-salicyaldehyde. The kinetic resolution selectivities of the aerobic oxidation process are in the range of 12 to >1000 based on the selectivity factors (k(rel)).
Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan. ctchen@mx.nthu.edu.tw
Chien-Tien
CT
Chen
Jun-Qi
JQ
Kao
Santosh B
SB
Salunke
Ya-Hui
YH
Lin
D002384:Catalysis; D005998:Glycine / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D013237:Stereoisomerism; D014639:Vanadium / Q000737:chemistry*
D007659:Ketones; D009942:Organometallic Compounds; D010087:Oxides; D014639:Vanadium; D010100:Oxygen; D005998:Glycine