Organocatalytic, Asymmetric Synthesis of 3-SulfenylatedN-Boc-Protected Oxindoles
摘要:
Sulfenylated oxindoles: The first asymmetric sulfenylation of N-Boc-protected oxindoles has been developed to provide products containing a tetrasubstituted stereogenic center in high to excellent yields (86-98 %) and, in most cases, excellent enantioselectivities (up to 96 % ee; see scheme).
An efficient method for the preparation of 3-sulfonylated 3,3-disubstituted oxindole derivatives has been developed. The protocol involves a base-catalyzed addition of sulfinatesalts to 3-halooxindoles, affording a wide range of 3-sulfonylated 3,3-disubstituted oxindoles in good to excellent yields under mild conditions. A preliminary trial of asymmetric catalytic version was conducted and gave promising