Copper-catalysed approach to spirocyclic oxindoles via a direct C–H, Ar-H functionalisation
作者:Catherine L. Moody、Vilius Franckevičius、Pauline Drouhin、Johannes E.M.N. Klein、Richard J.K. Taylor
DOI:10.1016/j.tetlet.2012.01.120
日期:2012.4
A practical and efficient entry to spirocyclic oxindoles from readily accessible anilide precursors, using only catalytic amounts of an inexpensive copper salt together with air as the sole re-oxidant, is described. In addition to providing access to a broad range of spiro-oxindole products, the utility of this method is demonstrated in a formal synthesis of the natural product, horsfiline. (C) 2012 Elsevier Ltd. All rights reserved.
Ynesulfonamide-Based Silica Gel and Alumina-Mediated Diastereoselective Cascade Cyclizations to Spiro[indoline-3,3′-pyrrolidin]-2-ones under Neat Conditions
spiro[indoline‐3,3′‐pyrrolidin]‐2‐ones were synthesized via a silica gel and alumina‐mediated sequential transformation based on tryptamine‐derived ynesulfonamide substrates under neat conditions. The inherent tendency of C−C bond migration through Wagner‐Meerwein rearrangement in the synthesis of spirooxindole was prevented by water trapping to the spiroindoleninium intermediate. The functional group tolerances