Packaging 500 mg in glass bottle Legal Information A Product of Onyx Scientific, U.K. Application Features: • Highly efficient • Excellent enantioselectivities • Available in both enantiomers • Operationally simple transformationsCatalyst for the enantioselective Weitz-Scheffer epoxidation of α,β-unsaturated aldehydes.1Condensation of this secondary amine with an aldehyde reversibly generates a β-fluoroiminium species where the fluorine atom is positioned gauche to the electropositive nitrogen centre.2Consequently, the phenyl substituents on the fluorine bearing carbon are placed in a predictable region of space. One of the groups effectively shields the upper face of the pendant iminium chain.Addition of hydrogen peroxide occurs in a highly selective manner to furnish optically enriched epoxides with excellent levels of enantiocontrol (Scheme 1).Simple α,β-disubstituted enals such as trans-cinnamaldehyde are smoothly converted to the corresponding epoxy aldehydes (up to 96% ee) as are their aliphatic analogues. The enantioselective, catalytic epoxidation of more challenging cyclic α,α,β-trisubstituted enals, and even an example of a α,α,β,β-tetrasubstituted enal, proceed with good yields and excellent enantioselectivities (up to 98% ee)3 (Scheme 2). |
包装 500 mg in glass bottle Legal Information 英国 Onyx Scientific 产品 Application Features: • Highly efficient • Excellent enantioselectivities • Available in both enantiomers • Operationally simple transformationsCatalyst for the enantioselective Weitz-Scheffer epoxidation of α,β-unsaturated aldehydes.1Condensation of this secondary amine with an aldehyde reversibly generates a β-fluoroiminium species where the fluorine atom is positioned gauche to the electropositive nitrogen centre.2Consequently, the phenyl substituents on the fluorine bearing carbon are placed in a predictable region of space. One of the groups effectively shields the upper face of the pendant iminium chain.Addition of hydrogen peroxide occurs in a highly selective manner to furnish optically enriched epoxides with excellent levels of enantiocontrol (Scheme 1).Simple α,β-disubstituted enals such as trans-cinnamaldehyde are smoothly converted to the corresponding epoxy aldehydes (up to 96% ee) as are their aliphatic analogues. The enantioselective, catalytic epoxidation of more challenging cyclic α,α,β-trisubstituted enals, and even an example of a α,α,β,β-tetrasubstituted enal, proceed with good yields and excellent enantioselectivities (up to 98% ee)3 (Scheme 2). |