Metallacarbenes from Diazoalkanes: An Experimental and Computational Study of the Reaction Mechanism. Cohen, R., Rybtchinski, B., Gandelman, M., Rozenberg, H., Martin, J. M L, & Milstein, D. Journal of the American Chemical Society, 125:6532-6546, 5, 2003. doi abstract bibtex PCP ligand (1,3-bis-[(diisopropyl-phosphanyl)-methyl]-benzene), and PCN ligand ([3-[(di-tert-butyl-phosphanyl)-methyl]-benzyl]-diethyl-amine) based rhodium dinitrogen complexes (1 and 2, respectively) react with phenyl diazomethane at room temperature to give PCP and PCN-Rh carbene complexes (3 and 5, respectively). At low temperature (-70 degrees C), PCP and PCN phenyl diazomethane complexes (4 and 6, respectively) are formed upon addition of phenyl diazomethane to 1 and 2. In these complexes, the diazo moiety is eta(1) coordinated through the terminal nitrogen atom. Decomposition of complexes 4 and 6 at low temperatures leads only to a relatively small amount of the corresponding carbene complexes, the major products of decomposition being the dinitrogen complexes 1 and 2 and stilbene. This and competition experiments (decomposition of 6 in the presence of 1) suggests that phenyl diazomethane can dissociate under the reaction conditions and attack the metal center through the diazo carbon producing a eta(1)-C bound diazo complex. Computational studies based on a two-layer ONIOM model, using the mPW1K exchange-correlation functional and a variety of basis sets for PCP based systems, provide mechanistic insight. In the case of less bulky PCP ligand bearing H-substituents on the phosphines, a variety of mechanisms are possible, including both dissociative and nondissociative pathways. On the other hand, in the case of i-Pr substituents, the eta(1)-C bound diazo complex appears to be a critical intermediate for carbene complex formation, in good agreement with the experimental results. Our results and the analysis of reported data suggest that the outcome of the reaction between a diazoalkane and a late transition metal complex can be anticipated considering steric requirements relevant to eta(1)-C diazo complex formation.
@article{jmlm162,
shorthand={162},
abstract = {PCP ligand (1,3-bis-[(diisopropyl-phosphanyl)-methyl]-benzene), and PCN ligand ([3-[(di-tert-butyl-phosphanyl)-methyl]-benzyl]-diethyl-amine) based rhodium dinitrogen complexes (1 and 2, respectively) react with phenyl diazomethane at room temperature to give PCP and PCN-Rh carbene complexes (3 and 5, respectively). At low temperature (-70 degrees C), PCP and PCN phenyl diazomethane complexes (4 and 6, respectively) are formed upon addition of phenyl diazomethane to 1 and 2. In these complexes, the diazo moiety is eta(1) coordinated through the terminal nitrogen atom. Decomposition of complexes 4 and 6 at low temperatures leads only to a relatively small amount of the corresponding carbene complexes, the major products of decomposition being the dinitrogen complexes 1 and 2 and stilbene. This and competition experiments (decomposition of 6 in the presence of 1) suggests that phenyl diazomethane can dissociate under the reaction conditions and attack the metal center through the diazo carbon producing a eta(1)-C bound diazo complex. Computational studies based on a two-layer ONIOM model, using the mPW1K exchange-correlation functional and a variety of basis sets for PCP based systems, provide mechanistic insight. In the case of less bulky PCP ligand bearing H-substituents on the phosphines, a variety of mechanisms are possible, including both dissociative and nondissociative pathways. On the other hand, in the case of i-Pr substituents, the eta(1)-C bound diazo complex appears to be a critical intermediate for carbene complex formation, in good agreement with the experimental results. Our results and the analysis of reported data suggest that the outcome of the reaction between a diazoalkane and a late transition metal complex can be anticipated considering steric requirements relevant to eta(1)-C diazo complex formation.},
author = {Revital Cohen and Boris Rybtchinski and Mark Gandelman and Haim Rozenberg and Jan M L Martin and David Milstein},
doi = {10.1021/ja028923c},
issn = {0002-7863},
issue = {21},
journal = {Journal of the American Chemical Society},
month = {5},
pages = {6532-6546},
pmid = {12785793},
title = {Metallacarbenes from Diazoalkanes: An Experimental and Computational Study of the Reaction Mechanism},
volume = {125},
year = {2003},
}
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{"_id":"cofrmpCknzwBAp6G8","bibbaseid":"cohen-rybtchinski-gandelman-rozenberg-martin-milstein-metallacarbenesfromdiazoalkanesanexperimentalandcomputationalstudyofthereactionmechanism-2003","author_short":["Cohen, R.","Rybtchinski, B.","Gandelman, M.","Rozenberg, H.","Martin, J. M L","Milstein, D."],"bibdata":{"bibtype":"article","type":"article","shorthand":"162","abstract":"PCP ligand (1,3-bis-[(diisopropyl-phosphanyl)-methyl]-benzene), and PCN ligand ([3-[(di-tert-butyl-phosphanyl)-methyl]-benzyl]-diethyl-amine) based rhodium dinitrogen complexes (1 and 2, respectively) react with phenyl diazomethane at room temperature to give PCP and PCN-Rh carbene complexes (3 and 5, respectively). At low temperature (-70 degrees C), PCP and PCN phenyl diazomethane complexes (4 and 6, respectively) are formed upon addition of phenyl diazomethane to 1 and 2. In these complexes, the diazo moiety is eta(1) coordinated through the terminal nitrogen atom. Decomposition of complexes 4 and 6 at low temperatures leads only to a relatively small amount of the corresponding carbene complexes, the major products of decomposition being the dinitrogen complexes 1 and 2 and stilbene. This and competition experiments (decomposition of 6 in the presence of 1) suggests that phenyl diazomethane can dissociate under the reaction conditions and attack the metal center through the diazo carbon producing a eta(1)-C bound diazo complex. Computational studies based on a two-layer ONIOM model, using the mPW1K exchange-correlation functional and a variety of basis sets for PCP based systems, provide mechanistic insight. In the case of less bulky PCP ligand bearing H-substituents on the phosphines, a variety of mechanisms are possible, including both dissociative and nondissociative pathways. On the other hand, in the case of i-Pr substituents, the eta(1)-C bound diazo complex appears to be a critical intermediate for carbene complex formation, in good agreement with the experimental results. Our results and the analysis of reported data suggest that the outcome of the reaction between a diazoalkane and a late transition metal complex can be anticipated considering steric requirements relevant to eta(1)-C diazo complex formation.","author":[{"firstnames":["Revital"],"propositions":[],"lastnames":["Cohen"],"suffixes":[]},{"firstnames":["Boris"],"propositions":[],"lastnames":["Rybtchinski"],"suffixes":[]},{"firstnames":["Mark"],"propositions":[],"lastnames":["Gandelman"],"suffixes":[]},{"firstnames":["Haim"],"propositions":[],"lastnames":["Rozenberg"],"suffixes":[]},{"firstnames":["Jan","M","L"],"propositions":[],"lastnames":["Martin"],"suffixes":[]},{"firstnames":["David"],"propositions":[],"lastnames":["Milstein"],"suffixes":[]}],"doi":"10.1021/ja028923c","issn":"0002-7863","issue":"21","journal":"Journal of the American Chemical Society","month":"5","pages":"6532-6546","pmid":"12785793","title":"Metallacarbenes from Diazoalkanes: An Experimental and Computational Study of the Reaction Mechanism","volume":"125","year":"2003","bibtex":"@article{jmlm162,\nshorthand={162},\n abstract = {PCP ligand (1,3-bis-[(diisopropyl-phosphanyl)-methyl]-benzene), and PCN ligand ([3-[(di-tert-butyl-phosphanyl)-methyl]-benzyl]-diethyl-amine) based rhodium dinitrogen complexes (1 and 2, respectively) react with phenyl diazomethane at room temperature to give PCP and PCN-Rh carbene complexes (3 and 5, respectively). At low temperature (-70 degrees C), PCP and PCN phenyl diazomethane complexes (4 and 6, respectively) are formed upon addition of phenyl diazomethane to 1 and 2. In these complexes, the diazo moiety is eta(1) coordinated through the terminal nitrogen atom. Decomposition of complexes 4 and 6 at low temperatures leads only to a relatively small amount of the corresponding carbene complexes, the major products of decomposition being the dinitrogen complexes 1 and 2 and stilbene. This and competition experiments (decomposition of 6 in the presence of 1) suggests that phenyl diazomethane can dissociate under the reaction conditions and attack the metal center through the diazo carbon producing a eta(1)-C bound diazo complex. Computational studies based on a two-layer ONIOM model, using the mPW1K exchange-correlation functional and a variety of basis sets for PCP based systems, provide mechanistic insight. In the case of less bulky PCP ligand bearing H-substituents on the phosphines, a variety of mechanisms are possible, including both dissociative and nondissociative pathways. On the other hand, in the case of i-Pr substituents, the eta(1)-C bound diazo complex appears to be a critical intermediate for carbene complex formation, in good agreement with the experimental results. Our results and the analysis of reported data suggest that the outcome of the reaction between a diazoalkane and a late transition metal complex can be anticipated considering steric requirements relevant to eta(1)-C diazo complex formation.},\n author = {Revital Cohen and Boris Rybtchinski and Mark Gandelman and Haim Rozenberg and Jan M L Martin and David Milstein},\n doi = {10.1021/ja028923c},\n issn = {0002-7863},\n issue = {21},\n journal = {Journal of the American Chemical Society},\n month = {5},\n pages = {6532-6546},\n pmid = {12785793},\n title = {Metallacarbenes from Diazoalkanes: An Experimental and Computational Study of the Reaction Mechanism},\n volume = {125},\n year = {2003},\n}\n","author_short":["Cohen, R.","Rybtchinski, B.","Gandelman, M.","Rozenberg, H.","Martin, J. 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