222533-60-0Relevant academic research and scientific papers
Molybdenum-catalyzed asymmetric allylic alkylation of 3-alkyloxindoles: Reaction development and applications
Trost, Barry M.,Zhang, Yong
, p. 2916 - 2922 (2011/05/02)
We report a full account of our work towards the development of Mo-catalyzed asymmetric allylic alkylation reactions with 3-alkyloxindoles as nucleophiles. The reaction is complementary to the Pd-catalyzed reaction with regard to the scope of oxindole nucleophiles. A number of 3-alkyloxindoles were alkylated successfully under mild conditions to give products with excellent yields and good-to-excellent enantioselectivities. Applications of this method to the preparation of indoline alkaloids such as (-)-physostigmine, ent-(-)-debromoflustramine B, and the indolinoquinoline rings of communesin B are reported.
Asymmetric synthesis of pyrrolidinoindolines. Application for the practical total synthesis of (-)-phenserine
Huang, Audris,Kodanko, Jeremy J.,Overman, Larry E.
, p. 14043 - 14053 (2007/10/03)
A versatile route to enantiopure 3,3-disubstituted oxindoles and 3a-substituted pyrrolidinoindolines is described in which diastereoselective dialkylation of enantiopure ditriflate 10 with oxindole enolates is the central step. These reactions are rare examples of alkylations of prostereogenic enolates with chiral sp3 electrophiles that proceed with high facial selectivity (10-20:1). The scope of this method is explored, and a model to rationalize the sense of stereoselection is advanced. This dialkylation chemistry was used to synthesize (-)-phenserine on a multigram scale in six steps and 43% overall yield from 5-methoxy-1,3-dimethyloxindole (27) and to complete a short formal total synthesis of (-)-physostigmine (2).
