Abstract
To advance the catalytic applications of s-block mixed-metal complexes, sodium magnesiate [NaMg(CH2SiMe3)3] (1) is reported as an efficient precatalyst for the guanylation of a variety of anilines and secondary amines with carbodiimides. First examples of hydrophosphination of carbodiimides by using a Mg catalyst are also described. The catalytic ability of the mixed-metal system is much greater than that of its homometallic components [NaCH2SiMe3 ] and [Mg(CH2SiMe3)2]. Stoichiometric studies suggest that magnesiate amido and guanidinate complexes are intermediates in these catalytic routes. Reactivity and kinetic studies imply that these guanylation reactions occur via (tris)amide intermediates that react with carbodiiimides in insertion steps. The rate law for the guanylation of N,N'-diisopropylcarbodiimide with 4-tert-butylaniline catalyzed by 1 is first order with respect to [amine], [carbodiimide], and [catalyst], and the reaction shows a large kinetic isotopic effect, which is consistent with an amine-assisted rate-determining carbodiimide insertion transition state. Studies to assess the effect of sodium in these transformations denote a secondary role with little involvement in the catalytic cycle.
| Language | English |
|---|---|
| Pages | 17646-17656 |
| Number of pages | 11 |
| Journal | Chemistry - A European Journal |
| Volume | 22 |
| Issue number | 49 |
| Early online date | 27 Oct 2016 |
| DOIs | |
| Publication status | Published - 5 Dec 2016 |
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Keywords
- cooperative effects
- guanidines
- homogeneous catalysis
- magnesiates
- s-block metals
- sodium magnesiate
- hydrophosphination
- carbodiimides
- guanylation reactions
Cite this
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Structural and mechanistic insights into s-block bimetallic catalysis : sodium magnesiate-catalyzed guanylation of amines. / De Tullio, Marco; Hernán-Gómez, Alberto; Livingstone, Zoe; Clegg, William; Kennedy, Alan R.; Harrington, Ross W.; Antiñolo, Antonio; Martínez, Antonio; Carrillo-Hermosilla, Fernando; Hevia, Eva.
In: Chemistry - A European Journal, Vol. 22, No. 49, 05.12.2016, p. 17646-17656.Research output: Contribution to journal › Article
TY - JOUR
T1 - Structural and mechanistic insights into s-block bimetallic catalysis
T2 - Chemistry - A European Journal
AU - De Tullio, Marco
AU - Hernán-Gómez, Alberto
AU - Livingstone, Zoe
AU - Clegg, William
AU - Kennedy, Alan R.
AU - Harrington, Ross W.
AU - Antiñolo, Antonio
AU - Martínez, Antonio
AU - Carrillo-Hermosilla, Fernando
AU - Hevia, Eva
N1 - This is the peer reviewed version of the following article: De Tullio, M., Hernán-Gómez, A., Livingstone, Z., Clegg, W., Kennedy, A. R., Harrington, R. W., ... Hevia, E. (2016). Structural and mechanistic insights into s-block bimetallic catalysis: sodium magnesiate-catalyzed guanylation of amines. Chemistry - A European Journal, 22(49), 17646-17656, which has been published in final form at https://dx.doi.org/10.1002/chem.201602906. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
PY - 2016/12/5
Y1 - 2016/12/5
N2 - To advance the catalytic applications of s-block mixed-metal complexes, sodium magnesiate [NaMg(CH2SiMe3)3] (1) is reported as an efficient precatalyst for the guanylation of a variety of anilines and secondary amines with carbodiimides. First examples of hydrophosphination of carbodiimides by using a Mg catalyst are also described. The catalytic ability of the mixed-metal system is much greater than that of its homometallic components [NaCH2SiMe3 ] and [Mg(CH2SiMe3)2]. Stoichiometric studies suggest that magnesiate amido and guanidinate complexes are intermediates in these catalytic routes. Reactivity and kinetic studies imply that these guanylation reactions occur via (tris)amide intermediates that react with carbodiiimides in insertion steps. The rate law for the guanylation of N,N'-diisopropylcarbodiimide with 4-tert-butylaniline catalyzed by 1 is first order with respect to [amine], [carbodiimide], and [catalyst], and the reaction shows a large kinetic isotopic effect, which is consistent with an amine-assisted rate-determining carbodiimide insertion transition state. Studies to assess the effect of sodium in these transformations denote a secondary role with little involvement in the catalytic cycle.
AB - To advance the catalytic applications of s-block mixed-metal complexes, sodium magnesiate [NaMg(CH2SiMe3)3] (1) is reported as an efficient precatalyst for the guanylation of a variety of anilines and secondary amines with carbodiimides. First examples of hydrophosphination of carbodiimides by using a Mg catalyst are also described. The catalytic ability of the mixed-metal system is much greater than that of its homometallic components [NaCH2SiMe3 ] and [Mg(CH2SiMe3)2]. Stoichiometric studies suggest that magnesiate amido and guanidinate complexes are intermediates in these catalytic routes. Reactivity and kinetic studies imply that these guanylation reactions occur via (tris)amide intermediates that react with carbodiiimides in insertion steps. The rate law for the guanylation of N,N'-diisopropylcarbodiimide with 4-tert-butylaniline catalyzed by 1 is first order with respect to [amine], [carbodiimide], and [catalyst], and the reaction shows a large kinetic isotopic effect, which is consistent with an amine-assisted rate-determining carbodiimide insertion transition state. Studies to assess the effect of sodium in these transformations denote a secondary role with little involvement in the catalytic cycle.
KW - cooperative effects
KW - guanidines
KW - homogeneous catalysis
KW - magnesiates
KW - s-block metals
KW - sodium magnesiate
KW - hydrophosphination
KW - carbodiimides
KW - guanylation reactions
UR - http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1521-3765
U2 - 10.1002/chem.201602906
DO - 10.1002/chem.201602906
M3 - Article
VL - 22
SP - 17646
EP - 17656
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 49
ER -