Stereoselective Synthesis of Pyrroloisoindolone and Pyridoisoindolone via aza-Prins Cyclization of Endocyclic <i>N</i>‑Acyliminium Ions

A simple methodology has been developed for the synthesis of substituted pyrroloisoindolone and pyridoisoindolone via aza-Prins cyclization of endocyclic <i>N</i>-acyliminium ions, which are derived from the triflic acid treatment of regioselectively reduced <i>N</i>-homopropargyl imides in excellent yields. The reaction is highly diastereoselective, and only one diastereoisomer is formed during the reaction. The methodology can be utilized for the synthesis of pyrimidoisoindole

Diastereoselective Synthesis of Substituted Morpholines from <i>N</i>‑Tethered Alkenols: Total Synthesis of (±)-Chelonin A

Intramolecular cyclization of nitrogen tethered alkenols catalyzed by palladium chloride leads to substituted morpholines in good yields. The methodology was used for the total synthesis of (±)-chelonin A

Diastereoselective Synthesis of Substituted Tetrahydrofurans via Prins Cyclization of Enol Ethers

Indium triflate can be efficiently used for Prins cyclization of acrylyl enol ethers to give tetrahydrofuran ring stereo- and regioselectively in good yields. The formation of five-membered rings is against the Baldwin’s rule

Stereo- and Regioselective Synthesis of 4‑Vinylpyrrolidine from N‑Tethered Alkyne-Alkenol

Indium­(III) chloride can be efficiently used for the synthesis of 4-vinylpyrrolidine from N-tethered alkyne-alkenol in good yields. The reaction is highly stereo- and regioselective

Diastereoselective Synthesis of Substituted Tetrahydrothiopyrans via (3,5)-Thionium–Ene Cyclization Reaction

Tetrahydrothiopyrans have been efficiently synthesized in good yields with excellent diastereoselectivity from aldehydes and substituted 5-methylhex-4-ene-1-thiol via (3,5)-thionium–ene cyclization reaction mediated by boron trifluoride etherate

Diastereoselective Synthesis of Substituted Tetrahydrothiophenes and -thiopyrans via Thia-Prins Cyclization Reaction

Tetrahydrothiophenes and -thiopyrans have been efficiently synthesized from thioacrylates via thia-Prins cyclization reaction mediated by trimethyl­silyl­trifluoro­methane­sulfonate with good diastereoselectivity and in good to high yields

Diastereoselective Synthesis of Substituted Tetrahydrothiopyrans via (3,5)-Thionium–Ene Cyclization Reaction

Tetrahydrothiopyrans have been efficiently synthesized in good yields with excellent diastereoselectivity from aldehydes and substituted 5-methylhex-4-ene-1-thiol via (3,5)-thionium–ene cyclization reaction mediated by boron trifluoride etherate

Synthesis of Tetrahydro‑1<i>H</i>‑indeno[1,2‑<i>b</i>]pyridine via Cascade Cyclization and Friedel–Crafts Reaction

A convenient protocol has been established for the synthesis of 1-tosyl-2,3,4,5-tetrahydro-1<i>H</i>-indeno­[1,2-<i>b</i>]­pyridine via cascade cyclization and Friedel–Crafts reaction of 4-methyl-<i>N</i>-(pent-4-yn-1-yl)­benzenesulfonamides and aldehydes in good yields. The methodology has been used for the total synthesis of the antidepressant agent (±)-5-phenyl-2,3,4,4a,5,9b-hexahydro-1<i>H</i>-indeno­[1,2-<i>b</i>]­pyridine

Diastereoselective Synthesis of Dihydropyrans via Prins Cyclization of Enol Ethers: Total Asymmetric Synthesis of (+)-Civet Cat Compound

Trimethylsilyl trifluoromethanesulfonate (TMSOTf) can be efficiently used for Prins cyclization of acrylyl enol ethers to 5,6-dihydro-2<i>H</i>-pyran-2-acetates stereo- and regioselectively in good yields. The methodology was used for the total synthesis of natural product (+)-civet

Stereoselective Synthesis of Amido and Phenyl Azabicyclic Derivatives via a Tandem Aza Prins-Ritter/Friedel–Crafts Type Reaction of Endocyclic <i>N</i>‑Acyliminium Ions

A simple protocol is described for the synthesis of amido and phenyl hexahydroindolizin-3­(2<i>H</i>)-one, hexahydro-1<i>H</i>-quinolizin-4­(6<i>H</i>)-one, and 1,3,4,10<i>b</i>-tetrahydropyrido­[2,1<i>-a</i>]­isoindol-6­(2<i>H</i>)-one derivatives via endo-trig (aza-Prins type) cyclization followed by an intermolecular Ritter/Friedel–Crafts reaction of cyclic <i>N</i>-acyliminium ions, which are derived from the boron trifluoride etherate treatment of regioselectively reduced <i>N</i>-homoallyl imides. The reactions are highly diastereoselective with excellent yields