65130-81-6Relevant academic research and scientific papers
Benzylamines via Iron-Catalyzed Direct Amination of Benzyl Alcohols
Yan, Tao,Feringa, Ben L.,Barta, Katalin
, p. 381 - 388 (2016/01/12)
Benzylamines play a prominent role in numerous pharmaceutically active compounds. Thus, the development of novel, sustainable catalytic methodologies to provide access to these privileged structural motifs is of central importance. Herein we describe a systematic study for the construction of a large variety of benzylamines using a well-defined homogeneous iron complex. The methodology consists of the direct coupling of readily available benzyl alcohols with simpler amines through the borrowing hydrogen methodology, producing a variety of substituted secondary and tertiary benzylamines in moderate to excellent yields for the first time with an iron catalyst. Notably, we explore the versatility of this methodology in the one-pot synthesis of nonsymmetric tertiary amines, sequential functionalization of diols with distinctly different amines, and the synthesis of N-benzyl piperidines via various synthetic pathways. In addition, direct conversion of the renewable building block 2,5-furan-dimethanol to pharmaceutically relevant compounds is achieved.
Reductive alkylation of thioamides with Grignard reagents in the presence of Ti(O i Pr)4: Insight and extension
Hermant, Fabien,Urbaska, Ewelina,Seizilles De Mazancourt, Sarah,Maubert, Thomas,Nicolas, Emmanuel,Six, Yvan
supporting information, p. 5643 - 5653 (2015/02/19)
The reductive alkylation of thioamides by Grignard reagents in the presence of Ti(OiPr)4 is the subject of a study involving 20 different substrates. The influence of various parameters has been evaluated, showing notably that the yields of this moderately efficient process can be improved in several cases by applying a slow addition of the Grignard reagent. The results presented in this contribution also provide new insight into the reactivity of the proposed key intermediates, namely, a metalated iminium species and, ultimately, an α-metalated amine. Interestingly, by control of the temperature and the amount of Grignard reagent engaged, the reaction can be directed toward the selective formation of the former titanium intermediate complex. This represents an extension of the original method, allowing the synthesis of various previously inaccessible substituted amines by subsequent addition of a nucleophilic reagent. This role can be played not only by organomagnesium compounds but also by alkyllithium reagents, alkyltitanium(IV) complexes, and lithium aluminum hydride. The properties of the α-metalated amine final intermediate have also been explored, demonstrating that this complex is a poor nucleophile but can act as a radical precursor, which is especially evidenced when the resulting radical species are stabilized. Overall, this chemistry thus proves unexpectedly rich and can plausibly lay the basis for the development of new applications in the future.
Synthesis of Amines via Carbon-Sulfur Bond Cleavages of Substituted Aminomethyl Sulfides with Organolithium Reagents: Aminocarbene Route to Enamines and Sterically Hindered Amines
Eisch, John J.,McNulty, John F.,Shi, Xian
, p. 7 - 9 (2007/10/02)
N-Substituted and N,N-disubstituted aminomethyl sulfides can be converted into secondary and tertiary amines, respectively, by organolithium reagents in high yields, regardless of whether the N-substituent is alkyl or aryl; for the former case, imines, and for the latter case, aminocarbenes, are the most likely intermediates.
