1033076-19-5Relevant articles and documents
Intramolecular hydroamination reactions catalyzed by zirconium complexes bearing bridged bis(phenolato) ligands
Zhang, Yu,Sun, Qiu,Wang, Yaorong,Yuan, Dan,Yao, Yingming,Shen, Qi
, p. 10541 - 10548 (2016)
Zirconium complexes stabilized by piperazidine- and imidazolidine-bridged bis(phenolato) ligands have been synthesized and characterized. Their activities in catalyzing intramolecular hydroamination reactions have been tested and compared, which reveals the significant role that the ancillary ligands play in influencing catalytic activities. Cationic species derived from zirconium dibenzyl complexes showed good activities in catalyzing intramolecular hydroamination reactions of both primary and secondary amines, and afforded the respective N-heterocycles in 85% to 99% yields. Moreover, this catalytic system also catalyzed sequential cyclization of primary aminodienes, and generated bicyclic tertiary amines in 94-99% yields.
A New N-Trityl-Substituted Aminopyridinato Titanium Catalyst for Hydroamination and Hydroaminoalkylation Reactions - Unexpected Intramolecular C-H Bond Activation
Lühning, Lars H.,Brahms, Christian,Nimoth, Jelte P.,Schmidtmann, Marc,Doye, Sven
, p. 2071 - 2082 (2015/10/19)
Sterically demanding 2,6-bis(tritylamino)pyridine is used for the synthesis of a mono(2,6-diaminopyridinato) titanium complex that undergoes unexpected intramolecular C-H bond activation to give access to an unusual 1-titanaisoindoline derivative. Both titanium complexes do not show high catalytic activity for hydroaminoalkylation reactions of alkenes but exceptional results are obtained in the field of alkene, alkyne, and allene hydroamination including room temperature activity for intramolecular alkene hydroamination, excellent regioselectivity of intermolecular alkyne and allene hydroamination as well as selectivity for hydroamination over hydroaminoalkylation during cyclization reactions of primary aminoalkenes.
2-Aminopyridinate titanium complexes for the catalytic hydroamination of primary aminoalkenes
Chong, Eugene,Qayyum, Sadaf,Schafer, Laurel L.,Kempe, Rhett
, p. 1858 - 1865 (2013/05/09)
A series of mono(2-aminopyridinato)tris(dimethylamido) titanium complexes, ApTi(NMe2)3 (where Ap = 2-aminopyridinato), have been prepared via protonolysis, and their reactivity for the hydroamination of primary aminoalkenes has been explored. The Ti complex incorporating N,6-dimesityl-2-aminopyridinate as the supporting ancillary ligand has been shown to yield a catalyst suitable for room-temperature intramolecular hydroamination reactions to give gem-disubstituted five-and six-membered-ring products. The comparison of ApTi(NMe2)3 with other group 4 catalysts shows that controlling the steric environment at the metal center is the critical determining factor for hydroamination reactivity. The screening of known challenging primary aminoalkene substrates with the most reactive ApTi(NMe2)3 shows good breadth of reactivity for the reaction. This complex is not able to cyclize secondary aminoalkene substrates, suggesting this reaction proceeds via an intermediate imido [2+2] cycloaddition pathway. An Ap-supported Ti imido complex, which also exhibits hydroamination activity, has been prepared and fully characterized from ApTi(NMe 2)3 and 2,6-dimethylaniline.
