H2, Pt. vs. H2, Lindlar's Catalyst

[HowAboutDAT]

Whats the difference between treating an alkene or alkyne with H2 Pt or H2, Lindlar's Catalyst?

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[pbure9]

H2 with Pt on an Alkene or Alkyne gives you the Alkane.

H2 and Lindlars works on alkynes and stops the reduction at the cis-alkene.

Na, NH3 is used for the trans-alkene.

Hope this helps!

 

[BiomajorPreDent]

Alkene -> H2/Pt -> alkane

Alkyne + H2/Pt -> alkane

now when you want to stop the Alkyne at the alkene stage you can use either lindlars catalyst (quinoline) or Na (or Li) in liquid ammonia

lindlars catalyst will give you the cis alkene

Na (or Li) in liquid ammonia will give you the trans alkene

 

[The Anhedonia]

now when you want to stop the Alkyne at the alkene stage you can use either lindlars catalyst (quinoline) or Na (or Li) in liquid ammonia

really? i never learned that (not that i'm doubting you).

 

[gentile1225]

another point i dont think anyone mentioned, not only does H2 give you an alkane, but it is a syn addition and is known as a selective reduction.

 

[BiomajorPreDent]

another point i dont think anyone mentioned, not only does H2 give you an alkane, but it is a syn addition and is known as a selective reduction.

Oh good catch thats right I forgot about that.