- Catalytic guanylation of aliphatic, aromatic, heterocyclic primary and secondary amines using nanocrystalline zinc(II) oxide
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Nanocrystalline ZnO was found to be a highly efficient heterogeneous catalyst for the guanylation of amines with various carbodiimides to afford N,N′,N″-trisubstituted guanidines in excellent yields. Structurally divergent aliphatic, aromatic, heterocyclic primary and secondary amines were converted to the corresponding N,N′,N″-trisubstituted guanidines using optimal conditions. The catalyst was easy to handle even under atmospheric conditions and can be easily recovered by centrifugation and reused for five cycles with consistent activity.
- Kantam, M. Lakshmi,Priyadarshini,Amal Joseph,Srinivas,Vinu,Klabunde,Nishina, Yuta
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experimental part
p. 5730 - 5737
(2012/09/08)
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- Titanacarborane mediated C-N bond forming/breaking reactions
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Constrained-geometry titanacarboranes [σ:η1:η5-(OCH2)(R2NCH2)C2B9H9]Ti(NR2) (R = Me, Et) are synthesized via an unexpected reaction of [Me3NH][μ-7,8-CH2OCH2-7,8-C2B9H10] with Ti(NR2)4 (R = Me, Et), involving a C-O bond cleavage and C-N bond formation. These complexes can be readily converted to new amide species or alkoxide by reacting with amines or esters, respectively. Insertion of a series of unsaturated molecules into the Ti-N bond of the aforementioned complexes results in the formation of various half-sandwich titanacarboranes. [σ:η1:η5-(OCH2)(Me2NCH2)C2B9H9]Ti(NMe2) is also able to efficiently catalyze the hydroamination of carbodiimides and the transamination of guanidines. These results are summarized in this brief account.
- Shen, Hao,Xie, Zuowei
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scheme or table
p. 1652 - 1657
(2009/10/11)
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