Author Topic: Lewis acids in Friedel-Crafts alkylations  (Read 1397 times)

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Mikael_Bakunin

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Lewis acids in Friedel-Crafts alkylations
« on: January 03, 2004, 03:24:00 PM »
Searching turned up:

Post 439768 (missing)

(Lego: "P2Ps from benzenes by Friedel-Crafts reaction", Methods Discourse)


In this reference the authors alkylate benzene with an substituted monochloroacetone derivate. They use SnCl4 for this purpose and tell the activity of catalysts, Lewis-acids usable in this synthesis is:
AlCl3 = SnCl4 > TiCl4 > ZnCl2

This baffled me as up to now I thought the activity is more like:
AlCl3 > FeCl3 > SnCl4 = ZnCl2

At least this is what most literature I read on this reaction said also there was no real consens - only SnCl4 was widely regarded as being not very active.

If SnCl4 is usable for a chloroacetone - benzene coupling I hope this might help to avoid excessive polymerization/polyalkylation.

Has somebody experiences or otherwise knowledge on Friedel-Crafts alkylations with other Lewis acids than AlCl3, preferable with benzene as aromatic compound?


btw. my question is on Lewis acids, not on the dangers of chloroacetone - this compound seems to trigger rather hysteric outbreaks it seems.

Major_Armstrong

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See Post 255616 Post 255661
« Reply #1 on: January 04, 2004, 07:22:00 PM »
See

Post 255616 (missing)

(PolytheneSam: "Re: Substituted P2P's:  Would this work?", Novel Discourse)

Post 255661 (missing)

(PolytheneSam: "Re: Substituted P2P's:  Would this work?", Novel Discourse)

Mikael_Bakunin

  • Guest
Thanks Major
« Reply #2 on: January 06, 2004, 05:18:00 AM »
Thats quite a lot to read - I will go over it and ask again so need is.
Hydrated ferric chloride - this to work on a unsubstituted benzene ring would be the hit of course.

Reading time again.