33925-51-8Relevant academic research and scientific papers
Efficient and Clean Nickel Catalyzed α-Allylation Reaction of Nitriles
Mouhsine, Bouchaib,Karim, Abdallah,Dumont, Clément,Suisse, Isabelle,Sauthier, Mathieu
supporting information, p. 1457 - 1462 (2021/02/16)
A clean method has been developed for the α-allylation of phenyl and alpha alkyl phenyl acetonitrile with allylic alcohols. The reaction is catalyzed by nickel complexes in situ generated from a combination of Ni(cod)2 and the dppf ligand and performed at 80 °C in methanol as reaction solvent.Accordingly to this simple and base-free protocol that only yields water as a side-product, many allylic nitriles were synthetized with good yields. (Figure presented.).
Pd-Catalyzed Intramolecular Aminoalkylation of Unactivated Alkenes: Access to Diverse N-Heterocycles
Ye, Liu,Lo, Kai-Yip,Gu, Qiangshuai,Yang, Dan
supporting information, p. 308 - 311 (2017/04/21)
A highly efficient palladium-catalyzed intramolecular aminoalkylation of unactivated alkenes in the absence of an external ligand and oxidant is described. New C-N and C(sp3)-C(sp3) bonds are formed simultaneously. This general transformation allows for construction of diverse N-heterocycles. Mechanistic studies show that the process may involve a four-membered Pd(alkyl)amido intermediate.
Switchable Stereoselectivity in Bromoaminocyclization of Olefins: Using Br?nsted Acids of Anionic Chiral Cobalt(III) Complexes
Jiang, Hua-Jie,Liu, Kun,Yu, Jie,Zhang, Ling,Gong, Liu-Zhu
supporting information, p. 11931 - 11935 (2017/09/20)
Br?nsted acids of anionic chiral CoIII complexes act as bifunctional phase-transfer catalysts to shuttle the substrates across the solvent interface and control stereoselectivity. The diastereomeric chiral CoIII-templated Br?nsted ac
I2-Mediated oxidative bicyclization of 4-pentenamines to prolinol carbamates with CO2 incorporating oxyamination of the C=C bond
Wang, Sheng,Zhang, Xiaowei,Cao, Chengyao,Chen, Chao,Xi, Chanjuan
supporting information, p. 4515 - 4519 (2017/10/13)
A metal-free oxyamination reaction of alkenes with ambient CO2 is reported. In the presence of I2 and DBU, CO2 is applied in situ as a protecting group to regulate the nucleophilicity of the amino group and facilitate the bicyclization of 4-pentenamines with high chemoselectivity. Moreover, this reaction provided a feasible approach to prepare prolinol carbamates with good tolerance of functional groups and high efficiency under mild conditions.
Niobium-Catalyzed Intramolecular Addition of O-H and N-H Bonds to Alkenes: A Tool for Hydrofunctionalization
Ferrand, Laura,Tang, Yue,Aubert, Corinne,Fensterbank, Louis,Mouriès-Mansuy, Virginie,Petit, Marc,Amatore, Muriel
supporting information, p. 2062 - 2065 (2017/04/28)
A convenient, versatile, and easy to handle intramolecular hydrofunctionalization of alkenes (C-O and C-N bonds formation) is reported using a novel niobium-based catalytic system. This atom economic and eco-friendly methodology provides an additional synthetic tool for the straightforward formation of valuable building blocks enabling molecular complexity. Various pyran, furan, pyrrolidine, piperidine, lactone, and lactam derivatives as well as spirocyclic compounds are produced in high yields and selectivities.
Copper(II)-catalyzed enantioselective intramolecular cyclization of N-alkenylureas
Fu, Shaomin,Yang, Honghao,Deng, Yuanfu,Jiang, Huanfeng,Zeng, Wei,Li, Guoqiang
supporting information, p. 1018 - 1021 (2015/03/30)
The first Cu(II)-catalyzed highly enantioselective intramolecular cyclization of N-alkenylureas was developed for the concise assembly of chiral vicinal diamino bicyclic heterocycles. Facile removal of carbonyl group of the carbamido moiety allowed for ready access to enantioenriched cyclic vicinal diamines.
6-azabicyclo[3.2.1]octanes via copper-catalyzed enantioselective alkene carboamination
Casavant, Barbara J.,Hosseini, Azade S.,Chemler, Sherry R.
supporting information, p. 2697 - 2702 (2014/09/29)
Bridged bicyclic rings containing nitrogen heterocycles are important motifs in bioactive small organic molecules. An enantioselective copper-catalyzed alkene carboamination reaction that creates bridged heterocycles is reported herein. Two new rings are
Deacylative allylation: Allylic alkylation via retro-Claisen activation
Grenning, Alexander J.,Tunge, Jon A.
supporting information; experimental part, p. 14785 - 14794 (2011/11/04)
A new method for allylic alkylation of a variety of relatively nonstabilized carbon nucleophiles is described herein. In this process of "deacylative allylation", the coupling partners, an allylic alcohol and a ketone pronucleophile, undergo in situ retro-Claisen activation to generate an allylic acetate and a carbanion. In the presence of palladium, these reactive intermediates undergo catalytic coupling to form a new C-C bond. In comparison to unimolecular decarboxylative allylation, a commonly utilized method for allylation of carbon anions, deacylative allylation is an intermolecular process. Moreover, deacylative allylation allows the direct coupling of readily available allylic alcohols. Lastly, the full utility of deacylative allylation is demonstrated by the rapid construction of a variety 1,6-heptadienes via 3-component couplings.
Intramolecular hydroamination of aminoalkenes by calcium and magnesium complexes: A synthetic and mechanistic study
Crimmin, Mark R.,Arrowsmith, Merle,Barrett, Anthony G. M.,Casely, Ian J.,Hill, Michael S.,Procopiou, Panayiotis A.
supporting information; experimental part, p. 9670 - 9685 (2011/03/20)
The β-diketiminate-stabilized calcium amide complex [{ArNC(Me)CHC(Me)NAr}Ca{N(SiMe3)2}-(THF)] (Ar = 2,6-diisopropylphenyl) and magnesium methyl complex [{ArNC(Me)CHC(Me)NAr}Mg(Me) (THF)] are reported as efficient precatalysts for hydroamination/cyclization of aminoalkenes. The reactions proceeded under mild conditions, allowing the synthesis of five-, six-, and seven-membered heterocyclic compounds. Qualitative assessment of these reactions revealed that the ease of catalytic turnover increases (i) for smaller ring sizes (5 > 6 > 7), (ii) substrates that benefit from favorable Thorpe-Ingold effects, and (iii) substrates that do not possess additional substitution on the alkene entity. Prochiral substrates may undergo diastereoselective hydroamination/cyclization depending upon the position of the existing stereocenter. Furthermore, a number of minor byproducts of these reactions, arising from competitive alkene isomerization reactions, were identified. A series of stoichiometric reactions between the precatalysts and primary amines provided an important model for catalyst initiation and suggested that these reactions are facile at room temperature, with the reaction of the calcium precatalyst with benzylamine proceeding with ΔG°(298 K) = -2.7 kcal mol-1. Both external amine/amide exchange and coordinated amine/amide exchange were observed in model complexes, and the data suggest that these processes occur via low-activation-energy pathways. As a result of the formation of potentially reactive byproducts such as hexamethyldisilazane, calcium-catalyst initiation is reversible, whereas for the magnesium precatalyst, this process is nonreversible. Further stoichiometric reactions of the two precatalysts with 1-amino-2,2-diphenyl-4-pentene demonstrated that the alkene insertion step proceeds via a highly reactive transient alkylmetal intermediate that readily reacts with N-H σ bonds under catalytically relevant conditions. The results of deuterium-labeling studies are consistent with the formation of a single transient alkyl complex for both the magnesium and calcium precatalysts. Kinetic analysis of the nonreversible magnesium system revealed that the reaction rate depends directly upon catalyst concentration and inversely upon substrate concentration, suggesting that substrate-inhibited alkene insertion is rate-determining.
Reverse Cope Elimination Reactions. 1. Mechanism and Scope
Ciganek, Engelbert,Read, John M.,Calabrese, Joseph C.
, p. 5795 - 5802 (2007/10/03)
N-4-Pentenyl- and N-5-hexenyl-N-methylhydroxylamine cyclized under mild conditions in a reverse Cope elimination reaction to give 1,2-dimethylpyrrolidine N-oxide and 1,2-dimethylpiperidine N-oxide, respectively.The reaction was shown to be concerted and thermodynamically controlled.The scope of this novel cyclization is discussed, and comparisons are made with the closely related and previously reported cyclization of monosubstituted alkenylhydroxylamines to give cyclic hydroxylamines.
