FeCl₃‐Catalyzed Ring‐Closing Carbonyl–Olefin Metathesis

Abstract

Exploiting catalytic carbonyl-olefin metathesis is an ongoing challenge in organic synthesis.R eported herein is an FeCl 3 -catalyzed ring-closing carbonyl-olefin metathesis.T he protocol allows access to arange of carbo-/heterocyclic alkenes with good efficiency and excellent trans diastereoselectivity. The methodology presents one of the rare examples of catalytic ring-closing carbonyl-olefin metathesis.T his process is proposed to take place by FeCl 3 -catalyzed oxetane formation followed by retro-ring-opening to deliver metathesis products.Ring-closing metathesis (RCM) of two carbon-carbon double bonds is one of the most significant reactions for the synthesis of various-sized rings (Figure 1a). [1] Thei mpact of RCM can be appreciated from its use in the synthesis of materials,drugs,natural products,etc. Inspired by the power of RCM, chemists are also interested in developing ringclosing carbonyl-olefin metathesis (RCCOM) of carbonylenes to synthesize ring compounds (Figure 1b). [2] First, the carbonyl group in carbonyl-enes are either readily available or easily prepared, while di-alkenes for RCM need more steps to be synthesized. Second, carbonyl-olefin metathesis is ap owerful means to synthesize highly substituted and otherwise difficult-to-obtain alkenes.H owever,t he reported RCCOM is realized by using as toichiometric amount of an RCM catalyst, such as titanium, molybdenum, or rhuthenium catalysts. [3] Them echanism of these reported RCCOM reactions involve the formation of the M=Or eagent. Gen-[ + + ]T hese authors contributed equally to this work.Supportinginformation for this article can be found under: http://dx.

Catalytic Isofunctional Reactions—Expanding the Repertoire of Shuttle and Metathesis Reactions

“…[97] EPR studies indicate the binding of FeCl 3 to the carbonyl group and attempts to trap any potential carbocation intermediates from geminal dimethyl-substituted alkenes failed. [100] Their procedure is similar to that employed by Schindler and co-workers,with the exception that aryl-substituted alkenes were studied. [99] Shortly after the initial publication from the group of Schindler,t he group of Li also reported an FeCl 3 -catalyzed ring-closing,c arbonyl/alkene metathesis.…”

Katalytische, isofunktionelle Reaktionen – Erweiterung des Repertoires an Shuttle‐ und Metathesereaktionen

“…[100] Ihre Versuchsvorschrift ähnelt derer von Schindler und Mitarbeitern, jedoch mit der Ausnahme,d ass arylsubstituierte Alkene untersucht wurden. [100] Ihre Versuchsvorschrift ähnelt derer von Schindler und Mitarbeitern, jedoch mit der Ausnahme,d ass arylsubstituierte Alkene untersucht wurden.…”