October 04, 2024, 10:49:49 PM
Forum Rules: Read This Before Posting


Topic: problem in wolf kishner mechanism  (Read 1984 times)

0 Members and 1 Guest are viewing this topic.

Offline ABA2015

  • Regular Member
  • ***
  • Posts: 44
  • Mole Snacks: +0/-2
problem in wolf kishner mechanism
« on: October 08, 2014, 04:48:20 AM »
hi all
I can't understand why in organic mechanisms some times an atom such as N can have 4 valence and indicates as N+ but sometimes not, for example in wolf Kirchner mechanism as follow, but in manich reaction N can be positive with 4 valence
« Last Edit: October 08, 2014, 05:04:56 AM by ABA2015 »

Offline ABA2015

  • Regular Member
  • ***
  • Posts: 44
  • Mole Snacks: +0/-2
Re: problem in wolf kishner mechanism
« Reply #1 on: October 08, 2014, 05:03:07 AM »
sorry I could not attach the mechanism
 the known intermediate of wolf kishner is for example in acetone reaction with hydrazine (CH3)2-HC-N=NH why this one is not observed (CH3)2-HC=N+=NH
« Last Edit: October 08, 2014, 05:14:58 AM by ABA2015 »

Offline mjc123

  • Chemist
  • Sr. Member
  • *
  • Posts: 2069
  • Mole Snacks: +302/-12
Re: problem in wolf kishner mechanism
« Reply #2 on: October 08, 2014, 05:19:06 AM »
Because (CH3)2HC=N+=NH would have a 5-valent carbon. (and where is the negative charge?)
In H2C+-NMe2 the carbon has six electrons and a vacant p orbital, so N can donate its lone pair to form a pi bond, and the formal + charge shifts from C to N.

Sponsored Links