Meyer–Schuster-Type Rearrangement of Propargylic Alcohols into α-Selenoenals and -enones with Diselenides

Abstract

We describe a mild and broadly applicable protocol for the preparation of a diverse array of multisubstituted αselenoenals and -enones from readily accessible propargylic alcohols and diselenides. The transformation proceeds via the Selectfluor-promoted selenirenium pathway, which enables selenenylation/rearrangement of a variety of propargylic alcohols. Gramscale experiments showed the potential of this synergistic protocol for practical application.

Synthesis of Spiro[5.5]trienones- and Spiro[4.5]trienones-Fused Selenocyanates via Electrophilic Selenocyanogen Cyclization and Dearomative Spirocyclization

“…In light of the above experiment results and according to previous work and the literature, , a plausible mechanism is depicted as shown in Scheme . First, The (SeCN) 2 generated from AgSeCN and NCS combines with substrate 1a to form selenonium ion A under the activation of FeCl 3 ·6H 2 O.…”

SelectfluorTM‐Mediated Tandem Fluorination and 1,3‐Carbonyl Migration in ortho‐Carbonyl Anilines: Charge‐Transfer‐Enabled ortho‐Selectivity

“…[7b] Scheme 1E demonstrates the conversion of propargylic alcohols (ix) to multisubstituted α-selenoenals or enones (x) via tandem selenenylation and Meyer-Schuster type rearrangement in presence of diaryl diselenides and selectfluor TM as oxidant. [8] To the best of our knowledge, selectfluor TM mediated domino fluorination and 1,3-carbonyl migration has never been reported.…”

“…An enantioselective fluorinative aza‐semipinacol rearrangement of cyclopropylamines type ( vii ) to β‐fluoro cyclobutylimines derivatives ( viii ) using combination of selectfluor TM and chiral ligand is also reported (Scheme 1D) [7b] . Scheme 1E demonstrates the conversion of propargylic alcohols ( ix ) to multisubstituted α‐selenoenals or enones ( x ) via tandem selenenylation and Meyer‐Schuster type rearrangement in presence of diaryl diselenides and selectfluor TM as oxidant [8] . To the best of our knowledge, selectfluor TM mediated domino fluorination and 1,3‐carbonyl migration has never been reported.…”

Regioselective intramolecular cyclization of o-alkynyl arylamines with the in situ formation of ArXCl to construct poly-functionalized 3-selenylindoles

“…Direct selenylation based on the indole compounds is one of the most classical synthetic methods to construct 3-selenylindoles. 8 Undeniably, 2-alkynylanilines are also powerful synthons for the synthesis of 3-selenylindoles 9–13 (Scheme 2).…”