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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Gulshan on June 13, 2007, 07:13:56 AM

Title: catalyst
Post by: Gulshan on June 13, 2007, 07:13:56 AM

please help in choosing transestrification catalyst in organic synthesis , that should be tin free ( non tin catalyst)

Title: Re: catalyst
Post by: Dan on June 13, 2007, 07:36:14 AM

Can you just use a protic acid? An acidic resin, sulfuric acid etc. or are you set on a non-protic lewis acid?

Title: Re: catalyst
Post by: kiwi on June 13, 2007, 05:30:47 PM

Titanium isopropoxide works wonders, if your substrate can tolerate it (and a lot can). Theres a paper by Seebach somewhere (Helv Chim Acta?) with the details. But if its neutral catalysts you want, you can't go past Oteras distannoxane catalysts, you can make them yourself, and they're active at really small loadings (at least 0.1 mol% from memory). They do contain two atoms of tin/molecule catalyst, but its only present in trace amounts.