4897-55-6Relevant articles and documents
Zirconium-hydride-catalyzed site-selective hydroboration of amides for the synthesis of amines: Mechanism, scope, and application
Han, Bo,Jiao, Haijun,Wu, Lipeng,Zhang, Jiong
, p. 2059 - 2067 (2021/09/02)
Developing mild and efficient catalytic methods for the selective synthesis of amines is a longstanding research objective. In this respect, catalytic deoxygenative amide reduction has proven to be promising but challenging, as this approach necessitates selective C–O bond cleavage. Herein, we report the selective hydroboration of primary, secondary, and tertiary amides at room temperature catalyzed by an earth-abundant-metal catalyst, Zr-H, for accessing diverse amines. Various readily reducible functional groups, such as esters, alkynes, and alkenes, were well tolerated. Furthermore, the methodology was extended to the synthesis of bio- and drug-derived amines. Detailed mechanistic studies revealed a reaction pathway entailing aldehyde and amido complex formation via an unusual C–N bond cleavage-reformation process, followed by C–O bond cleavage.
A practical catalytic reductive amination of carboxylic acids
Andrews, Keith G.,Denton, Ross M.,Hirst, David J.,Stoll, Emma L.,Tongue, Thomas,Valette, Damien
, p. 9494 - 9500 (2020/10/02)
We report reductive alkylation reactions of amines using carboxylic acids as nominal electrophiles. The two-step reaction exploits the dual reactivity of phenylsilane and involves a silane-mediated amidation followed by a Zn(OAc)2-catalyzed amide reduction. The reaction is applicable to a wide range of amines and carboxylic acids and has been demonstrated on a large scale (305 mmol of amine). The rate differential between the reduction of tertiary and secondary amide intermediates is exemplified in a convergent synthesis of the antiretroviral medicine maraviroc. Mechanistic studies demonstrate that a residual 0.5 equivalents of carboxylic acid from the amidation step is responsible for the generation of silane reductants with augmented reactivity, which allow secondary amides, previously unreactive in zinc/phenylsilane systems, to be reduced.
Dehydrogenative Aromatization and Sulfonylation of Pyrrolidines: Orthogonal Reactivity in Photoredox Catalysis
Muralirajan, Krishnamoorthy,Kancherla, Rajesh,Rueping, Magnus
supporting information, p. 14787 - 14791 (2018/10/20)
Oxidative dehydrogenative aromatization and selective sulfonylation reactions of N-heterocycles under visible-light photoredox catalysis were established. The mild reaction conditions make this approach an appealing and versatile strategy to functionalize/oxidize pyrrolidines whereby arylsulfonyl chlorides were identified to be both catalyst regeneration and sulfonylation reagents.
