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Ni(COD)2-Catalyzed ipso-Silylation of 2-Methoxynaphthalene: A Density Functional Theory Study.
- Source :
-
Organometallics . 4/9/2018, Vol. 37 Issue 7, p1141-1149. 9p. - Publication Year :
- 2018
-
Abstract
- Density functional theory has been used for the systematic investigation of the mechanism involved in Ni(COD)2-catalyzed ipso-silylation of 2-methoxynaphthalene. The two fundamental mechanistic pathways, internal nucleophilic substitution and a nonclassical oxidative addition, have been studied. In both pathways, the first equivalent of K+OtBu directly reacts with the silyl boronate (Et3SiBpin) to generate the silyl anion surrogate Et3SiK+ or silylborate [Et3Si-Bpin(OtBu)]K+ (IN3), which further reacts with Ni(COD)2 to form a substrate-catalyst complex, [(η2-COD)2NiSiEt3]K+. The internal nucleophilic substitution reaction pathway proceeds through η2 complexation of nickel with the C(1)=C(2) bond of 2-methoxynaphthalene. Later, nickel connects to =C(1) through σ-bond formation and coordinates with oxygen of the -OMe group. Simultaneously, the -SiEt3 group approaches =C(2) possessing -OMe followed by rearomatization which is facilitated by coordination of K++ with nickel and methoxy oxygen. In a nonclassical oxidative addition, the chelation of K++ with -OMe as well as -SiEt3 from [(η2-COD)2NiSiEt3] is the key step which promotes the insertion of NiSiEt3 to the =C(2) carbon of 2-methoxynaphthalene. We also observed that the activation energy barrier in the non-π-extended aromatic systems is higher than that of the π-extended aromatic systems. The overall study manifests that Ni(COD)2-catalyzed ipso-silylation of 2-methoxynapthalene operates through an internal nucleophilic substitution pathway. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02767333
- Volume :
- 37
- Issue :
- 7
- Database :
- Academic Search Index
- Journal :
- Organometallics
- Publication Type :
- Academic Journal
- Accession number :
- 129010026
- Full Text :
- https://doi.org/10.1021/acs.organomet.8b00046