23031-08-5Relevant academic research and scientific papers
Micellar Catalysis: Visible-Light Mediated Imidazo[1,2-a]pyridine C—H Amination with N-Aminopyridinium Salt Accelerated by Surfactant in Water
Yang, Zhonglie,Cao, Kun,Peng, Xiaoyan,Lin, Li,Fan, Danchen,Li, Jun-Long,Wang, Jingxia,Zhang, Xiaobin,Jiang, Hezhong,Li, Jiahong
supporting information, p. 3347 - 3352 (2021/10/20)
A light-promoted metal-free protocol for the amination of imidazo[1,2-a]pyridines with N-aminopyridinium salt by the assistance of surfactants in water was reported, charactering mild and environmentally benign conditions, as well as great functional grou
Visible-Light-Enabled Ortho-Selective Aminopyridylation of Alkenes with N-Aminopyridinium Ylides
Moon, Yonghoon,Lee, Wooseok,Hong, Sungwoo
supporting information, p. 12420 - 12429 (2020/07/24)
By utilizing an underexplored reactivity mode of N-aminopyridinium ylides, we developed the visible-light-induced ortho-selective aminopyridylation of alkenes via radical-mediated 1,3-dipolar cycloaddition. The photocatalyzed single-electron oxidation of N-aminopyridinium ylides generates the corresponding radical cations that enable previously inaccessible 1,3-cycloaddition with a broader range of alkene substrates. The resulting cycloaddition adducts rapidly undergo subsequent homolytic cleavage of the N-N bond, conferring a substantial thermodynamic driving force to yield various β-aminoethylpyridines. Remarkably, amino and pyridyl groups can be installed into both activated and unactivated alkenes with modular control of ortho-selectivity and 1,2-syn-diastereoselectivity under metal-free and mild conditions. Combined experimental and computational studies are conducted to clarify the detailed reaction mechanism and the origins of site selectivity and diastereoselectivity.
Aminohydroxylation of olefins with iminopyridinium ylides by dual Ir photocatalysis and Sc(OTf)3catalysis
Miyazawa, Kazuki,Koike, Takashi,Akita, Munetaka
, p. 7813 - 7820 (2016/11/16)
We have developed a new strategy for catalytic aminohydroxylation of olefins with an N-protected iminopyridinium ylide as the amine source. Iminopyridinium ylides N-protected with TFAc (trifluoroacetyl), Boc (tert-butoxycarbonyl), Troc (2,2,2-trichloroethoxycarbonyl), and Alloc (allyloxycarbonyl) groups serve as N-centered radical precursors when combined with fac-[Ir(ppy)3] photocatalysis and Sc(OTf)3catalysis. The dual Ir photoredox/Sc(OTf)3catalysis proves to be effective for aminohydroxylation of olefins under mild reaction conditions to provide 2-aminoalcohol derivatives bearing a primary amino group.
Benzoyl peroxide promoted radical ortho-alkylation of nitrogen heteroaromatics with simple alkanes and alcohols
Fang, Lei,Chen, Liangshun,Yu, Jianjun,Wang, Limin
supporting information, p. 1910 - 1914 (2015/03/18)
A catalytic amount of benzoyl peroxide (BPO)-initiated cross-dehydrogenative coupling reaction of N-iminopyridine ylides with simple alkanes and alcohols leads to the corresponding 2-alkylpyridines with high regioselectivity in moderate to good yields without an additional reduction step to remove the activated group. A catalytic amount of benzoyl peroxide (BPO)-initiated cross-dehydrogenative coupling reaction of N-iminopyridine ylides with simple alkanes and alcohols has been developed. The strategy allowed convenient access to various 2-alkylpyridines in moderate to good yields without an additional reduction step to remove the activated group.
Copper-catalyzed direct ortho-alkylation of N-iminopyridinium ylides with N-tosylhydrazones
Xiao, Qing,Ling, Lin,Ye, Fei,Tan, Renchang,Tian, Leiming,Zhang, Yan,Li, Yuxue,Wang, Jianbo
supporting information, p. 3879 - 3885 (2013/05/22)
Copper-catalyzed cross-coupling of N-tosylhydrazones with N-iminopyridinium ylides leads to the direct C-H alkylation. This direct C-H bond alkylation transformation uses inexpensive CuI as the catalyst without any ligand. The reaction is operationally simple and conducted under mild conditions, giving the corresponding alkylated pyridines in moderate to good yields. DFT calculation provides insights into the reaction mechanism, suggesting that the reaction proceeds through the Cu carbene migratory insertion process.
Highly regioselective synthesis of 2,4,5-(hetero)aryl substituted oxazoles by intermolecular [3+2]-cycloaddition of unsymmetrical internal alkynes
Chatzopoulou, Elli,Davies, Paul W.
supporting information, p. 8617 - 8619 (2013/09/23)
A robust N-nucleophilic 1,3-N,O-dipole equivalent reacts with unsymmetrical internal alkynes under gold catalysis. Conjugation from a remote nitrogen lone pair enables and controls this convergent and highly regioselective process.
Intermolecular and selective synthesis of 2,4,5-trisubstituted oxazoles by a gold-catalyzed formal [3+2] cycloaddition
Davies, Paul W.,Cremonesi, Alex,Dumitrescu, Lidia
supporting information; experimental part, p. 8931 - 8935 (2011/10/19)
Oxazole new world: A gold-catalyzed intermolecular reaction of pyridine-N-aminides with ynamides can be used to prepare trisubstituted 1,3-oxazoles with a variety of functional groups. This formal [3+2] cycloaddition employs robust conjugated N-ylides as
Synthesis of 2- and 2,3-substituted Pyrazolo[1,5- a ]pyridines: Scope and mechanistic considerations of a domino direct alkynylation and cyclization of n -iminopyridinium ylides using alkenyl bromides, alkenyl iodides, and alkynes
Mousseau, James J.,Bull, James A.,Ladd, Carolyn L.,Fortier, Angelique,Sustac Roman, Daniela,Charette, Andre B.
experimental part, p. 8243 - 8261 (2012/01/03)
Direct functionalization and tandem processes have both received considerable recent interest due to their cost and time efficiency. Herein we report the synthesis of difficult to obtain 2-substituted pyrazolo[1,5-a] pyridines through a tandem palladium-catalyzed/silver-mediated elimination/direct functionalization/cyclization reaction involving N-benzoyliminopyridinium ylides. As such, these biologically important molecules are prepared in an efficient, high-yielding manner, only requiring a two-step sequence from pyridine. Aryl-substituted alkenyl bromides and iodides are effective ylide coupling partners. Mechanistic studies led to the use of terminal alkynes, which extended the scope of the reaction to include alkyl substitution on the unsaturated reactive site. The optimization, scope, and mechanistic considerations of the process are discussed.
Copper-catalyzed direct alkenylation of N-iminopyridinium ylides
Mousseau, James J.,Bull, James A.,Charette, Andre B.
supporting information; experimental part, p. 1115 - 1118 (2010/05/17)
(Figure Presented) A versatile Cu-catalyzed direct C-H alkenylation of N-iminopyridinium ylides, compatible with several different copper sources (including a penny), provides a powerful and inexpensive method for the synthesis of functionalized pyridine derivatives. Chemoselective functionalization of halide-containing compounds allows the synthesis of alkenyl pyridines containing reactive tethers for further functionalization
The first aminimide synthesis from benzoyl azide and pyridine
Capuano, Ben,Crosby, Ian T.,Lloyd, Edward J.,Neve, Juliette E.
, p. 214 - 217 (2008/02/11)
Irradiation of benzoyl azide 1 at 254 nm in the presence of some amines produces aminimides: in the presence of pyridine the aminimide 13 can be isolated in 41% yield; in the presence of N,N-dimethylaniline a CH insertion product 7 is obtained via an intermediate aminimide 12. This is the first reported synthesis of aminimides from a benzoyl azide. CSIRO 2007.
