794-06-9Relevant academic research and scientific papers
Palladium-catalyzed benzylic C(sp3)-H carbonylative arylation of azaarylmethyl amines with aryl bromides
Hu, Bowen,Walsh, Patrick J.,Xu, Lijin,Zhao, Haoqiang
, p. 10862 - 10870 (2021/08/25)
A highly selective palladium-catalyzed carbonylative arylation of weakly acidic benzylic C(sp3)-H bonds of azaarylmethylamines with aryl bromides under 1 atm of CO gas has been achieved. This work represents the first examples of use of such weakly acidic pronucleophiles in this class of transformations. In the presence of a NIXANTPHOS-based palladium catalyst, this one-pot cascade process allows a range of azaarylmethylamines containing pyridyl, quinolinyl and pyrimidyl moieties and acyclic and cyclic amines to undergo efficient reactions with aryl bromides and CO to provide α-amino aryl-azaarylmethyl ketones in moderate to high yields with a broad substrate scope and good tolerance of functional groups. This reaction proceeds via in situ reversible deprotonation of the benzylic C-H bonds to give the active carbanions, thereby avoiding prefunctionalized organometallic reagents and generation of additional waste. Importantly, the operational simplicity, scalability and diversity of the products highlight the potential applicability of this protocol.
Pd0-Catalyzed Four-Component Reaction of Aryl Halide, CO, N-Tosylhydrazone, and Amine
Liu, Yiyang,Zhang, Zhen,Zhang, Songnan,Zhang, Yan,Wang, Jianbo,Zhang, Zhenhua
supporting information, p. 3658 - 3663 (2018/10/31)
A Pd0-catalyzed four-component cascade reaction of an aryl halide, CO, an N-tosylhydrazone, and an amine affording α-amino ketone has been developed. This reaction involves a sequential carbonylation, metal carbene migratory insertion, and amination. Control experiments and DFT calculations further reveal the reaction sequence and chemoselectivity of individual components in this cascade process.
A versatile and one-pot strategy to synthesize ?±-amino ketones from benzylic secondary alcohols using N -bromosuccinimide
Guha, Somraj,Rajeshkumar, Venkatachalam,Kotha, Surya Srinivas,Sekar, Govindasamy
, p. 406 - 409 (2015/03/04)
A metal-free one-pot strategy has been developed for the first time to synthesize pharmaceutically important ?±-amino ketones from readily available benzylic secondary alcohols and amines using N-bromosuccinimide. This new reaction proceeds via three consecutive steps involving oxidation of alcohols, ?±-bromination of ketones, and nucleophilic substitution of ?±-bromo ketones to give ?±-amino ketones. Importantly, this novel one-pot greener reaction avoids direct usage of toxic and corrosive bromine. This methodology has been employed efficiently to synthesize pharmaceutically important amfepramone and pyrovalerone in a single step.
Transition-metal-free oxidative α-C-H amination of ketones via a radical mechanism: Mild synthesis of α-amino ketones
Jiang, Qing,Xu, Bin,Zhao, An,Jia, Jing,Liu, Tian,Guo, Cancheng
, p. 8750 - 8756 (2015/01/08)
A transition-metal-free direct α-C.H amination of ketones has been developed using commercially available ammonium iodide as the catalyst and sodium percarbonate as the co-oxidant. A wide range of ketone ((hetero)aromatic or nonaromatic ketones) and amine (primary/secondary amines, anilines, or amides) substrates undergo cross-coupling to generate synthetically useful α-amino ketones. The mechanistic studies indicated that a radical pathway might be involved in the reaction process. The utility of the method is highlighted through a concise one-step synthesis of the pharmaceutical agent amfepramone.
NIS-catalyzed reactions: Amidation of acetophenones and oxidative amination of propiophenones
Lamani, Manjunath,Prabhu, Kandikere Ramaiah
supporting information, p. 14638 - 14642 (2013/01/15)
Single-step amination: The N-iodosuccinimide (NIS)-catalyzed amidation of acetophenone derivatives by using tert-butylhydroperoxide (TBHP) as an oxidant is presented. A variety of acetyl derivatives of heterocyclic compounds were easily converted to their corresponding ketoamides under these conditions. A new, NIS-catalyzed amination of propiophenone and its derivatives in the presence of TBHP to furnish the corresponding 2-aminoketone derivatives is the first reported single-step amination of propiophenone derivatives. Copyright
α-amino ketone synthesis from aldehydes and N-(α-dialkylaminoalkyl)benzotriazoles
Katritzky, Alan R.,Cheng, Dai,Musgrave, Richard P.
, p. 273 - 280 (2007/10/02)
Thiazolium salt-catalyzed reactions of aldehydes with morpholino-(alkylbenzotriazoles) allow the synthesis of a variety of α-amino ketones. The relationship between reaction conditions and selectivity is discussed.
Further evidences about the role of bis(thiazolin-2-ylidene)s as the actual catalytic species in the generalised benzoin condensation
Lopez-Calahorra, Francisco,Castro, Esther,Ochoa, Ana,Marti, Josep
, p. 5019 - 5022 (2007/10/03)
Applying our mechanistic hypothesis about the real catalytic species in the benzoin condensation catalysed by thiazosium salts plus bases, we have succeed in the extension to aldehydes different from formaldehyde of a previously described method of synthe
Studies on dioxirane chemoselectivity: The oxidation of an enamino moiety present in a Fischer carbene complex
Lluch, Anna-Maria,Gibert, Mariona,Sanchez-Baeza, Francisco,Messeguer, Angel
, p. 3973 - 3982 (2007/10/03)
The dimethyldioxirane (DMD) promoted oxidative decomplexation of Fischer carbene complex 1, which contains a conjugated enamino moiety, was investigted. Thus, treatment of 1 with 3 molecular equivalents of DMD afforded a 52% yield of amide 3 as unique isolable organic product. When the reaction was performed with 1 molecular equivalent of DMD the formation of the enol intermediate 15 was evidenced by its capture as the tetrafluoroboric acid salt 16. This salt was unstable and when it was exposed to air gave rise to amide 3 and to low amounts of ethyl benzoate and acetophenone. These results indicate that the presence of an enamino group conjugated to the Fischer carbene moiety inverts the chemoselectivity previously observed in the DMD promoted decomplexation of these compounds. Thus, the major pathway involves the oxidation of the enamino double bond through the formation of an enol intermediate which reacts with oxygen to give products resulting from the breakdown of the molecule.
Singlet oxygen mediated fragmentation of amino alcohols, 1,2-diamines, and amino ketones
Haugen, Christian M.,Bergmark, William R.,Whitten, David G.
, p. 10293 - 10297 (2007/10/02)
Irradiation of aerated solutions of singlet oxygen sensitizers such as Rose Bengal, Rose Bengal derivative, or palladium tetraphenylporphyrin in the presence of substituted amines (amino alcohols, 1,2-diamines, and amino ketones) results in oxidative fragmentation of the amine in good chemical yield and with low-to-moderate quantum efficiency. For the amino alcohols and 1,2-diamines the reaction course is similar to that initiated by irradiation of electron-transfer "sensitizers" such as thioindigo or cyanoaromatics. In these cases the reaction has been shown to proceed via single electron transfer oxidation of the amine and subsequent cleavage of the amine cation radical. A similar mechanism is proposed for the reaction with singlet oxygen sensitizers in which singlet oxygen initiates reaction by SET oxidation of the amine donors and subsequent reaction from the resulting superoxide-amine cation ion radical pair. For reaction with amino ketones under the same conditions, irradiation results in formation of novel fragmentation products incorporating oxygen. Labeling studies with O-18 enriched oxygen indicate that air is the source of certain of the incorporated oxygen in the products and suggest a mechanism closely related to the other fragmentation processes.
