Do non-classical carbanions exist?












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There are some non-classical carbocations, such as the 2-norbornyl cation, in which the positive charge is heavily delocalised. Have non-classical carbanions also been discovered? I have not seen any non-classical carbanions in books. If there are any non-classical carbanions, please provide some examples.










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    – orthocresol
    Dec 24 '18 at 2:26


















13












$begingroup$


There are some non-classical carbocations, such as the 2-norbornyl cation, in which the positive charge is heavily delocalised. Have non-classical carbanions also been discovered? I have not seen any non-classical carbanions in books. If there are any non-classical carbanions, please provide some examples.










share|improve this question











$endgroup$












  • $begingroup$
    If an answer has helped solve your question, please consider upvoting and/or accepting one (by clicking on the tick next to the voting buttons). That's the Stack Exchange way of saying thank you! See also: chemistry.stackexchange.com/help/someone-answers
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    – orthocresol
    Dec 24 '18 at 2:26
















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$begingroup$


There are some non-classical carbocations, such as the 2-norbornyl cation, in which the positive charge is heavily delocalised. Have non-classical carbanions also been discovered? I have not seen any non-classical carbanions in books. If there are any non-classical carbanions, please provide some examples.










share|improve this question











$endgroup$




There are some non-classical carbocations, such as the 2-norbornyl cation, in which the positive charge is heavily delocalised. Have non-classical carbanions also been discovered? I have not seen any non-classical carbanions in books. If there are any non-classical carbanions, please provide some examples.







organic-chemistry ions resonance






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edited Dec 23 '18 at 22:51









orthocresol

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38.7k7113235










asked Dec 16 '18 at 10:20









Saheb Garain great chemistSaheb Garain great chemist

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2 Answers
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In addition to the species mentioned in the answer above, I found another one in Organic Chemistry by Morrison and Boyd(Seventh Edition)enter image description here






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    Please give me some references
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    – Saheb Garain great chemist
    Dec 16 '18 at 16:32



















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Interesting question. It is much less studied and reported on than the case of non-classical carbocations, but I did find a few papers. Brown and Occolowitz (Brown, J. M.; Occolowitz, J. L. Chem. Commun. 1965, 376–377) reported that deuterated bicyclo[3.2.1]octa-2,6-diene 1b, below, undergoes base-catalysed de-deuteration (potassium tert-butoxide in DMSO) to give 1a much faster (ca. 3 x 10^4) than the bicyclo[3.2.1]octa-2-ene counterpart, ie. 2b -> 2a. They suggested this is evidence for the intermediacy of a 6π-electron, delocalised (non-classical) carbanion 3.



enter image description here



Much more recently, Brown reviewed and provided additional DFT computational evidence for stabilisation and charge delocalisation in these species (Brown, J. M. Aust. J. Chem. 2014, 67, 1296–1300).






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    2 Answers
    2






    active

    oldest

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    2 Answers
    2






    active

    oldest

    votes









    active

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    active

    oldest

    votes









    9












    $begingroup$

    In addition to the species mentioned in the answer above, I found another one in Organic Chemistry by Morrison and Boyd(Seventh Edition)enter image description here






    share|improve this answer











    $endgroup$









    • 1




      $begingroup$
      Please give me some references
      $endgroup$
      – Saheb Garain great chemist
      Dec 16 '18 at 16:32
















    9












    $begingroup$

    In addition to the species mentioned in the answer above, I found another one in Organic Chemistry by Morrison and Boyd(Seventh Edition)enter image description here






    share|improve this answer











    $endgroup$









    • 1




      $begingroup$
      Please give me some references
      $endgroup$
      – Saheb Garain great chemist
      Dec 16 '18 at 16:32














    9












    9








    9





    $begingroup$

    In addition to the species mentioned in the answer above, I found another one in Organic Chemistry by Morrison and Boyd(Seventh Edition)enter image description here






    share|improve this answer











    $endgroup$



    In addition to the species mentioned in the answer above, I found another one in Organic Chemistry by Morrison and Boyd(Seventh Edition)enter image description here







    share|improve this answer














    share|improve this answer



    share|improve this answer








    edited Dec 16 '18 at 16:57

























    answered Dec 16 '18 at 16:09









    YUSUF HASANYUSUF HASAN

    380213




    380213








    • 1




      $begingroup$
      Please give me some references
      $endgroup$
      – Saheb Garain great chemist
      Dec 16 '18 at 16:32














    • 1




      $begingroup$
      Please give me some references
      $endgroup$
      – Saheb Garain great chemist
      Dec 16 '18 at 16:32








    1




    1




    $begingroup$
    Please give me some references
    $endgroup$
    – Saheb Garain great chemist
    Dec 16 '18 at 16:32




    $begingroup$
    Please give me some references
    $endgroup$
    – Saheb Garain great chemist
    Dec 16 '18 at 16:32











    17












    $begingroup$

    Interesting question. It is much less studied and reported on than the case of non-classical carbocations, but I did find a few papers. Brown and Occolowitz (Brown, J. M.; Occolowitz, J. L. Chem. Commun. 1965, 376–377) reported that deuterated bicyclo[3.2.1]octa-2,6-diene 1b, below, undergoes base-catalysed de-deuteration (potassium tert-butoxide in DMSO) to give 1a much faster (ca. 3 x 10^4) than the bicyclo[3.2.1]octa-2-ene counterpart, ie. 2b -> 2a. They suggested this is evidence for the intermediacy of a 6π-electron, delocalised (non-classical) carbanion 3.



    enter image description here



    Much more recently, Brown reviewed and provided additional DFT computational evidence for stabilisation and charge delocalisation in these species (Brown, J. M. Aust. J. Chem. 2014, 67, 1296–1300).






    share|improve this answer











    $endgroup$


















      17












      $begingroup$

      Interesting question. It is much less studied and reported on than the case of non-classical carbocations, but I did find a few papers. Brown and Occolowitz (Brown, J. M.; Occolowitz, J. L. Chem. Commun. 1965, 376–377) reported that deuterated bicyclo[3.2.1]octa-2,6-diene 1b, below, undergoes base-catalysed de-deuteration (potassium tert-butoxide in DMSO) to give 1a much faster (ca. 3 x 10^4) than the bicyclo[3.2.1]octa-2-ene counterpart, ie. 2b -> 2a. They suggested this is evidence for the intermediacy of a 6π-electron, delocalised (non-classical) carbanion 3.



      enter image description here



      Much more recently, Brown reviewed and provided additional DFT computational evidence for stabilisation and charge delocalisation in these species (Brown, J. M. Aust. J. Chem. 2014, 67, 1296–1300).






      share|improve this answer











      $endgroup$
















        17












        17








        17





        $begingroup$

        Interesting question. It is much less studied and reported on than the case of non-classical carbocations, but I did find a few papers. Brown and Occolowitz (Brown, J. M.; Occolowitz, J. L. Chem. Commun. 1965, 376–377) reported that deuterated bicyclo[3.2.1]octa-2,6-diene 1b, below, undergoes base-catalysed de-deuteration (potassium tert-butoxide in DMSO) to give 1a much faster (ca. 3 x 10^4) than the bicyclo[3.2.1]octa-2-ene counterpart, ie. 2b -> 2a. They suggested this is evidence for the intermediacy of a 6π-electron, delocalised (non-classical) carbanion 3.



        enter image description here



        Much more recently, Brown reviewed and provided additional DFT computational evidence for stabilisation and charge delocalisation in these species (Brown, J. M. Aust. J. Chem. 2014, 67, 1296–1300).






        share|improve this answer











        $endgroup$



        Interesting question. It is much less studied and reported on than the case of non-classical carbocations, but I did find a few papers. Brown and Occolowitz (Brown, J. M.; Occolowitz, J. L. Chem. Commun. 1965, 376–377) reported that deuterated bicyclo[3.2.1]octa-2,6-diene 1b, below, undergoes base-catalysed de-deuteration (potassium tert-butoxide in DMSO) to give 1a much faster (ca. 3 x 10^4) than the bicyclo[3.2.1]octa-2-ene counterpart, ie. 2b -> 2a. They suggested this is evidence for the intermediacy of a 6π-electron, delocalised (non-classical) carbanion 3.



        enter image description here



        Much more recently, Brown reviewed and provided additional DFT computational evidence for stabilisation and charge delocalisation in these species (Brown, J. M. Aust. J. Chem. 2014, 67, 1296–1300).







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited Dec 24 '18 at 0:34









        orthocresol

        38.7k7113235




        38.7k7113235










        answered Dec 16 '18 at 13:46









        Organic Chemistry ExplainedOrganic Chemistry Explained

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