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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: vamsikrishna on March 26, 2017, 11:24:25 AM

Title: Palladium black
Post by: vamsikrishna on March 26, 2017, 11:24:25 AM

I have been using Chloro ((tri-tert-butylphosphine)-2-(2-aminobiphenyl) palladium  (II) as a catalyst and N,N-dicyclohexylmethylamine as base in Suzuki coupling a black sticky mass is getting formed in my vessel but when I use sodium tert-pentoxide as base in the reaction black sticky mass isn't forming, I did use H2SO4 and even HCl to dissolve the black sticky mass but I couldn't succeed but when I used 20% aq HBr the black sticky mass dissolved...Can someone kindly please say ASAP what would be the black sticky mass and why did it got dissolved only in Aq. HBr?

Title: Re: Palladium black
Post by: Aerosolid on March 27, 2017, 11:18:58 AM

What substrates are you coupling?

Title: Re: Palladium black
Post by: vamsikrishna on March 29, 2017, 04:55:33 AM

The substrates are aniline and methyl acrylate

Title: Re: Palladium black
Post by: Irlanur on March 29, 2017, 05:14:32 AM

Quote

Can someone kindly please say ASAP what would be the black sticky mass

AFAIK it's metallic Pd(0).

Title: Re: Palladium black
Post by: Irlanur on March 29, 2017, 05:22:16 AM

http://pubs.rsc.org/en/Content/ArticleLanding/2004/CC/b406719n#!divAbstract

DOI: 10.1039/B406719N

Title: Re: Palladium black
Post by: wildfyr on March 29, 2017, 08:28:06 AM

Won't aniline and methyl acrylate do a nice Michael addition on their own? Also if you're heating this methyl acrylate can oligomerize