The Epoxidation of Carbonyl Compounds with a Benzyne-Triggered Sulfur Ylide

Abstract

An efficient method for the synthesis of epoxides from carbonyl compounds, sulfoxides, and benzyne is presented. The strategy involved an epoxidation by a sulfur ylide which is formed in situ from sulfoxide and benzyne through the S-O bond insertion and deprotonation. This one-pot reaction proceeds under mild and base-free conditions, providing a convenient way to introduce the substituted methylene groups onto the carbonyl carbon.

Stereoselective synthesis and applications of spirocyclic oxindoles

“…59 Epoxidation of isatins and isatin derivatives. Though nonstereoselective, notable advances in the synthesis of spiroepoxyoxindoles have been made recently by Wang and Zhang, 60 and Pace. 61 Diastereoselective epoxidations have been developed, 62 notably the use of a trifluoroethylsulfonium salt in a Corey-Chaykovsky reaction by Cheng and Zhai.…”

Domino Processes of Arynes Reacting with Three Classes of Nucleophiles for Organic Syntheses

“…They are also able to synthesize o-haloaryl P-chirogenic phosphines from phosphine boranes and haloarynes in the presence of nbutyllithium. [10] Wang et al [11] use sulfoxides to react with two equivalents of benzynes and then N-methyl isatin in situ. The corresponding spiro[indoline-3,2'-oxiran]-2-ones are produced in a mixture of cis and trans isomers.…”

Efficient Catalytic Kinetic Resolution of Spiro‐epoxyoxindoles with Concomitant Asymmetric Friedel–Crafts Alkylation of Indoles

“…So far,n onterminal spiro-epoxyoxindoles could be obtained either by using chiral sulfur ylides or asymmetric Darzens reactions. Recently,w ith the development of more practical methods,such epoxides could be obtained easily in racemic mixtures, [5] and renders the catalytic kinetic resolution an attractive strategy for accessing optically active spiro-epoxyoxindoles. Though they could be used as key intermediates for the synthesis of XEN 402 [3a,b] and gliocladin C, [3c] surprisingly,the enantioselective method to access such compounds is still ac hallenge and has never been reported.…”

“…Though they could be used as key intermediates for the synthesis of XEN 402 [3a,b] and gliocladin C, [3c] surprisingly,the enantioselective method to access such compounds is still ac hallenge and has never been reported. Recently,w ith the development of more practical methods,such epoxides could be obtained easily in racemic mixtures, [5] and renders the catalytic kinetic resolution an attractive strategy for accessing optically active spiro-epoxyoxindoles.3-Indolyloxindoles,b earing an all-carbon quaternary center, are unique structural motifs found in aw ide range of bioactive natural products and pharmaceuticals. [6] Fore xample,3 -(3-indolyl)-oxindole-3-methanols have been used as key intermediates in the synthesis of gliocladin C [7] and could be potentially used in the total synthesis of other indole alkaloids with 3,3'-bis(indole) skeletons.…”

“…Though they could be used as key intermediates for the synthesis of XEN 402 [3a,b] and gliocladin C, [3c] surprisingly,the enantioselective method to access such compounds is still ac hallenge and has never been reported. Recently,w ith the development of more practical methods,such epoxides could be obtained easily in racemic mixtures, [5] and renders the catalytic kinetic resolution an attractive strategy for accessing optically active spiro-epoxyoxindoles.…”