39260-86-1Relevant academic research and scientific papers
Phosphine-Free Manganese Catalyst Enables Selective Transfer Hydrogenation of Nitriles to Primary and Secondary Amines Using Ammonia-Borane
Sarkar, Koushik,Das, Kuhali,Kundu, Abhishek,Adhikari, Debashis,Maji, Biplab
, p. 2786 - 2794 (2021/03/03)
Herein we report the synthesis of primary and secondary amines by nitrile hydrogenation, employing a borrowing hydrogenation strategy. A class of phosphine-free manganese(I) complexes bearing sulfur side arms catalyzed the reaction under mild reaction conditions, where ammonia-borane is used as the source of hydrogen. The synthetic protocol is chemodivergent, as the final product is either primary or secondary amine, which can be controlled by changing the catalyst structure and the polarity of the reaction medium. The significant advantage of this method is that the protocol operates without externally added base or other additives as well as obviates the use of high-pressure dihydrogen gas required for other nitrile hydrogenation reactions. Utilizing this method, a wide variety of primary and symmetric and asymmetric secondary amines were synthesized in high yields. A mechanistic study involving kinetic experiments and high-level DFT computations revealed that both outer-sphere dehydrogenation and inner-sphere hydrogenation were predominantly operative in the catalytic cycle.
Benzimidazole fragment containing Mn-complex catalyzed hydrosilylation of ketones and nitriles
Ganguli, Kasturi,Mandal, Adarsha,Sarkar, Bidisha,Kundu, Sabuj
, (2020/08/13)
The synthesis of a new bidentate (NN)–Mn(I) complex is reported and its catalytic activity towards the reduction of ketones and nitriles is studied. On comparing the reactivity of various other Mn(I) complexes supported by benzimidazole ligand, it was observed that the Mn(I) complexes bearing 6-methylpyridine and benzimidazole fragments exhibited the highest catalytic activity towards monohydrosilylation of ketones and dihydrosilylation of nitriles. Using this protocol, a wide range of ketones were selectively reduced to the corresponding silyl ethers. In case of unsaturated ketones, the chemoselective reduction of carbonyl group over olefinic bonds was observed. Additionally, selective dihydrosilylation of several nitriles were also achieved using this complex. Mechanistic investigations with radical scavengers suggested the involvement of radical species during the catalytic reaction. Stoichiometric reaction of the Mn(I) complex with phenylsilane revealed the formation of a new Mn(I) complex.
Regio- and stereoselective hydroamination of alkynes using an ammonia surrogate: Synthesis of N -Silylenamines as reactive synthons
Lui, Erica K. J.,Brandt, Jason W.,Schafer, Laurel L.
supporting information, p. 4973 - 4976 (2018/04/24)
An anti-Markovnikov selective hydroamination of alkynes with N-silylamines to afford N-silylenamines is reported. The reaction is catalyzed by a bis(amidate)bis(amido)Ti(IV) catalyst and is compatible with a variety of terminal and internal alkynes. Stoichiometric mechanistic studies were also performed. This method easily affords interesting N-silylenamine synthons in good to excellent yields and the easily removable silyl protecting group enables the catalytic synthesis of primary amines.
Rapid Conventional and Microwave-Assisted Decarboxylation of L-Histidine and Other Amino Acids via Organocatalysis with R-Carvone under Superheated Conditions
Jackson, Douglas M.,Ashley, Robert L.,Brownfield, Callan B.,Morrison, Daniel R.,Morrison, Richard W.
, p. 2691 - 2700 (2015/12/18)
This article reports a new methodology taking advantage of superheated chemistry via either microwave or conventional heating for the facile decarboxylation of alpha amino acids using the recoverable organocatalyst, R-carvone. The decarboxylation of amino acids is an important synthetic route to biologically active amines, and traditional methods of amino acid decarboxylation are time consuming (taking up to several days in the case of L-histidine), are narrow in scope, and make use of toxic catalysts. Decarboxylations of amino acids including L-histidine occur in just minutes while replacing toxic catalysts with green catalyst, spearmint oil. Yields are comparable to or exceed previous methods and purification of product ammonium chloride salts is aided by an isomerization reaction of residual catalyst to phenolic carvacrol. The method has been shown to be effective for the decarboxylations of a range of natural, synthetic, and protected amino acids.
METHODS AND COMPOSITIONS FOR SELECTIVE AND TARGETED CANCER THERAPY
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Page/Page column 228, (2015/03/28)
Provided herein are methods and compositions for selective and targeted cancer therapy, in particular certain benzothiophenes, benzothiazoles, oxalamides, N-acyl ureas and chromones, and their use in selectively treating certain adenocarcinomas. In some embodiments, the selective toxicity of the compounds may be mediated through SCD1 and/or CYP450 such as CYP4F11.
Phenethylamines via Heck Arylation of a New Vinylamine Equivalent
Busacca, Carl A.,Johnson, Robert E.,Swestock, John
, p. 3299 - 3303 (2007/10/02)
A new vinylamine equivalent, N-vinyloxazolone 3, has been prepared in three steps and shown to undergo Heck arylation with a variety of substrates.The Heck adducts thus obtained are then converted in one step and high yield to phenethylamine hydrochlorides.As a general synthetic method for preparation of substituted phenethylamines, use of this new reagent is shown to be superior to N-vinylphthalimide in number of steps, regiospecificity, and chemical yield.
