Comments on: Intramolecular Friedel-Crafts Reactions

By: Nucleophilic Acyl Substitution | UO Chemists

Nucleophilic Acyl Substitution | UO Chemists — Sat, 11 Nov 2023 14:50:03 +0000

[…] Intramolecular acylation reactions involve a cyclic structure where an internal nucleophile attacks an adjacent acyl group. These reactions often occur in ring systems and can lead to the formation of lactones or lactams, depending on the nature of the nucleophile. […]

By: James Ashenhurst

James Ashenhurst — Mon, 22 Aug 2022 20:06:26 +0000

In reply to m610105009@tmu.edu.tw. Good question. The carbonyl oxygen is activated by AlCl3. This sets up the carboxylate to act as a leaving group when the ring attacks at the sp3 hybridized carbon. That's the first Friedel-Crafts. The second Friedel Crafts is an acylation reaction where O-AlCl3(-) is the leaving group.

By: m610105009@tmu.edu.tw

m610105009@tmu.edu.tw — Sun, 21 Aug 2022 10:58:15 +0000

I wondered that the activated lactone by Alcl3 in answer #2 is which part in lactone reacted with Alcl3? Is the oxygen in lactone ring or the oxygen in carbonyl group? How should I choose from two of them?
Just like acyl chloride is the chloride react with the Alcl3

By: James Ashenhurst

James Ashenhurst — Thu, 04 Aug 2022 16:03:35 +0000

In reply to Paul Lee. Right. Try the alkylation first - your leaving group will be RCO2Alcl3, which will then be well primed for FC acylation

By: Is RCOOH + H2SO4 + heat a viable alternative to RCOCl + AlCl3 in Friedel-Crafts acylation? – CodePT

Tue, 26 Apr 2022 05:05:50 +0000

[…] It is best known for intramolecular cyclisation using Polyphosphoric Acid (PPA) or Methanesulfonic acid more here. […]

By: Is RCOOH + H2SO4 + heat a viable alternative to RCOCl + AlCl3 in Friedel-Crafts acylation? – NOWOO

Tue, 26 Apr 2022 05:05:33 +0000

[…] It is best known for intramolecular cyclisation using Polyphosphoric Acid (PPA) or Methanesulfonic acid more here. […]

By: Paul Lee

Paul Lee — Thu, 18 Feb 2021 17:46:31 +0000

I’m most of the way through the tetralone mechanism, but I can’t figure out the final dissociation of the aluminium complex. I had the bridging oxygen in the ester complex initially with the aluminium trichloride first, break the ring and the acylium formation. F-C acylation and rearomatization like normal, but here is where I’m confused. The aluminium centre has a negative charge, and the oxygen is no longer positively charged, so if the C-O bond breaks to alkylate, I have a doubly negative aluminium species. Where did I go wrong?
Thanks!

By: Anushka

Anushka — Sun, 24 May 2020 07:35:01 +0000

Sir please tell the mechanism when acid anhydride react with 2 eq of alcl3 with benzene

By: Friedel-Crafts Alkylation Reaction Mechanism With Examples

Friedel-Crafts Alkylation Reaction Mechanism With Examples — Mon, 10 Feb 2020 04:26:27 +0000

[…] Intramolecular Friedel-Crafts alkylation – com […]

By: James Ashenhurst

James Ashenhurst — Tue, 21 May 2019 16:29:21 +0000

In reply to Natoli Umer. It's a sequence of friedel-crafts acylation and then friedel-crafts alkylation. First step: AlCl3 reacts with the oxygen of the lactone, resulting in formation of the acylium ion which is attacked by the aromatic ring. Now you have an oxygen coordinated to AlCl3 (a good Lewis acid). The AlCl3 converts the oxygen into a good leaving group. So what can happen next is attack of the aromatic ring at the carbon bearing the oxygen, resulting in formation of a new six-membered ring.