Existence of non-classical carbanions











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We know that there are some non-classical carbocations. But have non-classical carbanions also been described? I have not seen non-classical carbanions in books. If there are any non-classical carbanions, please provide some examples






organic-chemistry ions







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  • What do you mean by"non classical carbanions"? Non classical carbocations are stabilised by resonance via sigma bonds to empty orbitals, while carbanions are destabilized by +H effect.
    – YUSUF HASAN
    7 hours ago










  • I mean to say that as nonclassical carbo cations are stabilized by the pi bond shifting which present in homo alylic or homo benzylic positions or they stabilized by sigma bond shifting, now I want to know that the type of stabilization which present in non classical carbo cations is it present in non classical Carbo anions, if they exist.
    – Saheb Garain great chemist
    7 hours ago

















up vote
9
down vote

favorite












We know that there are some non-classical carbocations. But have non-classical carbanions also been described? I have not seen non-classical carbanions in books. If there are any non-classical carbanions, please provide some examples






organic-chemistry ions







share|improve this question
























  • What do you mean by"non classical carbanions"? Non classical carbocations are stabilised by resonance via sigma bonds to empty orbitals, while carbanions are destabilized by +H effect.
    – YUSUF HASAN
    7 hours ago










  • I mean to say that as nonclassical carbo cations are stabilized by the pi bond shifting which present in homo alylic or homo benzylic positions or they stabilized by sigma bond shifting, now I want to know that the type of stabilization which present in non classical carbo cations is it present in non classical Carbo anions, if they exist.
    – Saheb Garain great chemist
    7 hours ago















up vote
9
down vote

favorite









up vote
9
down vote

favorite











We know that there are some non-classical carbocations. But have non-classical carbanions also been described? I have not seen non-classical carbanions in books. If there are any non-classical carbanions, please provide some examples






organic-chemistry ions







share|improve this question















We know that there are some non-classical carbocations. But have non-classical carbanions also been described? I have not seen non-classical carbanions in books. If there are any non-classical carbanions, please provide some examples






organic-chemistry ions




organic-chemistry ions






share|improve this question















share|improve this question













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share|improve this question








edited 1 hour ago









Jan

48.6k7114256




48.6k7114256










asked 7 hours ago









Saheb Garain great chemist

724




724












  • What do you mean by"non classical carbanions"? Non classical carbocations are stabilised by resonance via sigma bonds to empty orbitals, while carbanions are destabilized by +H effect.
    – YUSUF HASAN
    7 hours ago










  • I mean to say that as nonclassical carbo cations are stabilized by the pi bond shifting which present in homo alylic or homo benzylic positions or they stabilized by sigma bond shifting, now I want to know that the type of stabilization which present in non classical carbo cations is it present in non classical Carbo anions, if they exist.
    – Saheb Garain great chemist
    7 hours ago




















  • What do you mean by"non classical carbanions"? Non classical carbocations are stabilised by resonance via sigma bonds to empty orbitals, while carbanions are destabilized by +H effect.
    – YUSUF HASAN
    7 hours ago










  • I mean to say that as nonclassical carbo cations are stabilized by the pi bond shifting which present in homo alylic or homo benzylic positions or they stabilized by sigma bond shifting, now I want to know that the type of stabilization which present in non classical carbo cations is it present in non classical Carbo anions, if they exist.
    – Saheb Garain great chemist
    7 hours ago


















What do you mean by"non classical carbanions"? Non classical carbocations are stabilised by resonance via sigma bonds to empty orbitals, while carbanions are destabilized by +H effect.
– YUSUF HASAN
7 hours ago




What do you mean by"non classical carbanions"? Non classical carbocations are stabilised by resonance via sigma bonds to empty orbitals, while carbanions are destabilized by +H effect.
– YUSUF HASAN
7 hours ago












I mean to say that as nonclassical carbo cations are stabilized by the pi bond shifting which present in homo alylic or homo benzylic positions or they stabilized by sigma bond shifting, now I want to know that the type of stabilization which present in non classical carbo cations is it present in non classical Carbo anions, if they exist.
– Saheb Garain great chemist
7 hours ago






I mean to say that as nonclassical carbo cations are stabilized by the pi bond shifting which present in homo alylic or homo benzylic positions or they stabilized by sigma bond shifting, now I want to know that the type of stabilization which present in non classical carbo cations is it present in non classical Carbo anions, if they exist.
– Saheb Garain great chemist
7 hours ago












2 Answers
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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)






share|improve this answer




























    up vote
    3
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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






    share|improve this answer























    • Please give me some references
      – Saheb Garain great chemist
      1 hour ago











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    up vote
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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)






    share|improve this answer

























      up vote
      9
      down vote













      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























        up vote
        9
        down vote










        up vote
        9
        down vote









        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












        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










        answered 4 hours ago









        Organic Chemistry Explained

        69616




        69616






















            up vote
            3
            down vote













            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























            • Please give me some references
              – Saheb Garain great chemist
              1 hour ago















            up vote
            3
            down vote













            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























            • Please give me some references
              – Saheb Garain great chemist
              1 hour ago













            up vote
            3
            down vote










            up vote
            3
            down vote









            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














            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 1 hour ago

























            answered 2 hours ago









            YUSUF HASAN

            314211




            314211












            • Please give me some references
              – Saheb Garain great chemist
              1 hour ago


















            • Please give me some references
              – Saheb Garain great chemist
              1 hour ago
















            Please give me some references
            – Saheb Garain great chemist
            1 hour ago




            Please give me some references
            – Saheb Garain great chemist
            1 hour ago


















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