InCl3: A Mild Lewis Acid but Efficient Reagent in Organic Synthesis

A Versatile Indium Trichloride Mediated Prins-Type Reaction to Unsaturated Heterocycles

“…Typically, the cyclization partner has been either a carbonyl compound or epoxide, and of various Lewis acids screened for promoting this reaction, indium trichloride has been shown to be the most efficient (Scheme 1). 4 Results are presented herein to complement our previous report 3 and prove the previously postulated stereoselectivity of the silyl-Prins cyclization. Further, we shall describe the extension of this method to the preparation of heterocycles containing sulfur and nitrogen, as well as oxygen.…”

Indium(III) Chloride-Promoted Intramolecular Addition of Allylstannanes to Alkynes

“…A similar intramolecular allylation has been achieved by using electrophilic late transition metal chlorides such as PtCl 2 and AuCl 3 , which work as π-Lewis acids for electrophilic activation of alkynes . However, the present cyclizations are quite different from the π-Lewis acid-catalyzed cyclization in mechanistic aspects although InCl 3 is frequently utilized as a mild Lewis acid …”

Formal Syntheses of (±)-Platensimycin and (±)-Platencin via a Dual-Mode Lewis Acid Induced Cascade Cyclization Approach

“…Dual-mode Lewis acids − are useful for developing cascade cyclization reactions since they can induce cyclization reactions via forming σ- and/or π-complexes with the substrates as well as the intermediate(s) that are generated in situ. We are particularly interested in developing dual-mode Lewis acid induced cascade cyclization reactions for natural product syntheses since they can often construct the core structure of the synthetic target in a single operation under mild conditions. − Recently, we have developed the ZnBr 2 -catalyzed Diels–Alder (DA)/carbocyclization cascade cyclization reaction for the rapid construction of cis -hydrindanes and demonstrated its utilities in natural product synthesis .…”