500537-06-4Relevant academic research and scientific papers
Efficient One-Pot Reductive Aminations of Carbonyl Compounds with Aquivion-Fe as a Recyclable Catalyst and Sodium Borohydride
Airoldi, Veronica,Piccolo, Oreste,Roda, Gabriella,Appiani, Rebecca,Bavo, Francesco,Tassini, Riccardo,Paganelli, Stefano,Arnoldi, Sebastiano,Pallavicini, Marco,Bolchi, Cristiano
supporting information, p. 162 - 168 (2019/12/11)
A one-pot reductive amination of aldehydes and ketones with NaBH4 was developed with a view to providing efficient, economical and greener synthetic conditions. A recyclable iron-based Lewis catalyst, Aquivion-Fe, was used to promote imine formation in cyclopentyl methyl ether, followed by the addition of a small amount of methanol to the reaction mixture to enable C=N reduction by NaBH4. The protocol, applied to a wide number of amines and carbonyl compounds, resulted in ever complete conversion of these latter with excellent chemoselectivity towards the expected amination products in the most cases. Isolated yields, determined for a selection of the screened substrates, were found consistent with the previously obtained conversion and selectivity data. Cinacalcet, an important active pharmaceutical ingredient, was efficiently prepared by the title procedure.
Catalytic Asymmetric Synthesis of N-Chiral Amine Oxides
Bhadra, Sukalyan,Yamamoto, Hisashi
, p. 13043 - 13046 (2016/10/30)
Direct asymmetric synthesis of N-chiral amine oxides was accomplished (up to 91:9 e.r.) by means of a bimetallic titanium catalyst. A hydroxy group situated at the γ-position of the N stereocenter enables the desired N-oxidation through dynamic kinetic resolution of the trivalent amine substrates. The method was further extended to the kinetic resolution of racemic γ-amino alcohols with a preexisting stereocenter, giving an important class of enantioenriched (up to 99.9:0.1 e.r.) building blocks that are otherwise difficult to synthesize.
Rapid and efficient access to secondary arylmethylamines
Fleury-Brégeot, Nicolas,Raushel, Jessica,Sandrock, Deidre L.,Dreher, Spencer D.,Molander, Gary A.
, p. 9564 - 9570 (2012/08/28)
Ammoniomethyl trifluoroborates are very powerful reagents that can be used to access biologically relevant aryl- and heteroaryl-methylamine motifs via Suzuki-Miyaura cross-couplings. Until now, this method was limited to the production of tertiary and primary amines. The synthesis of a large array of secondary ammoniomethyltrifluoroborates has been achieved through a one step nucleophilic substitution reaction on the potassium bromomethyltrifluoroborate. Smooth cross-coupling conditions have been designed, based on the use of an aminobiphenyl palladium precatalyst, to couple these trifluoroborates efficiently with aryl bromides. This strategy offers a new way to access biologically relevant motifs and allows, with the previously developed methods, access to all three classes of aminomethylarenes. Secondary ammoniomethyltrifluoroborates can be easily synthesized by nucleophilic substitution on potassium bromomethyltrifluoroborate. These reagents have then been used in Suzuki-Miyaura cross-couplings with aryl bromides, offering an effective access to the aminomethylarene structural motif. This new method provides an interesting alternative to the reductive amination procedure (see scheme). Copyright
