51513-55-4Relevant academic research and scientific papers
Stereoselective control by face-to-face versus edge-to-face aromatic interactions: The case of C3-TiIV amino trialkolate sulfoxidation catalysts
Santoni, Gabriella,Mba, Miriam,Bonchio, Marcella,Nugent, William A.,Zonta, Cristiano,Licini, Giulia
experimental part, p. 645 - 654 (2010/05/18)
The stereoselective oxidation of differently functionalised benzyl phenyl sulfides has been examined by using enantiopure TiIV trialkanolamine complexes. These complexes efficiently catalyse the sulfoxidation with good stereoselectivities. The
Chemistry of oxaziridines. 17. N-(phenylsulfonyl)(3,3-dichlorocamphoryl)oxaziridine: A highly efficient reagent for the asymmetric oxidation of sulfides to sulfoxides
Davis, Franklin A.,Thimma Reddy,Han, Wei,Carroll, Patrick J.
, p. 1428 - 1437 (2007/10/02)
The synthesis, structure, and enantioselective oxidations of a new chiral N-sulfonyloxaziridine 12c [3,3-dichloro-1,7,7-trimethyl-2'-(phenylsulfonyl)spiro[bicyclo[2.2.1]heptane-2, 3'-oxaziridine]] are reported. This oxidant, which exhibits remarkably high and predictable ee's for the enantioselective oxidation of prochiral sulfides to sulfoxides, is prepared in three steps from (+)- or (-)-camphor in 50% overall yield. Steric effects are primarily responsible for the molecular recognition and are predictable using a simple active-site model where the nonbonded interactions between the RL and RS groups of the sulfide (RL-S-RS) and the active-site surface are minimized in a planar transition-state structure. The fact that alkyl aryl sulfides give high ee's in nonpolar solvents suggests that there is also a stereoelectronic component to the molecular recognition. High ee's (>90%) are anticipated for those sulfides where the difference in size of the groups directly bonded to the sulfur atom is large, i.e., aryl, tert-butyl vs CH2R (R = H, alkyl, benzyl, etc). The X-ray structure and studies with the dihydro, difluoro, and dibromo oxaziridines 12a, 12b, and 12d reveal that the exceptional enantioselectivities displayed by 12c are a consequence of a molecular cleft or groove, defined by the oxaziridine chlorine atoms and phenylsulfonyl group, on the active-site surface.
