98760-21-5Relevant academic research and scientific papers
Oxidative Amidation of Nitroalkanes with Amine Nucleophiles using Molecular Oxygen and Iodine
Li, Jing,Lear, Martin J.,Kawamoto, Yuya,Umemiya, Shigenobu,Wong, Alice R.,Kwon, Eunsang,Sato, Itaru,Hayashi, Yujiro
, p. 12986 - 12990 (2015)
The formation of amides and peptides often necessitates powerful yet mild reagent systems. The reagents used, however, are often expensive and highly elaborate. New atom-economical and practical methods that achieve such goals are highly desirable. Ideally, the methods should start with substrates that are readily available in both chiral and non-chiral forms and utilize cheap reagents that are compatible with a wide variety of functional groups, steric encumberance, and epimerizable stereocenters. A direct oxidative method was developed to form amide and peptide bonds between amines and primary nitroalkanes simply by using I2 and K2CO3 under O2. Contrary to expectations, a 1:1 halogen-bonded complex forms between the iodonium source and the amine, which reacts with nitronates to form α-iodo nitroalkanes as precursors to the amides.
Copper-Catalyzed Diamination of Unactivated Alkenes with Electron-Rich Amino Sources
Li, Yang,Ali, Arshad,Dong, Junchao,Zhang, Yu,Shi, Lili,Liu, Qun,Fu, Junkai
supporting information, p. 4072 - 4077 (2021/05/26)
The catalytic intermolecular diamination of unactivated alkenes with electron-rich amino sources is a challenge. Herein, by employing a directing-group strategy, a copper-catalyzed diamination of unactivated alkenes was realized. Symmetrical diamines were efficiently produced in a highly diastereoselective manner with readily available dialkylamines as amino sources, while a one-pot and two-step operation was necessary to produce the unsymmetrical diamines. These reactions were proposed to proceed through aziridinium intermediates.
Halogen Bonding of N-Halosuccinimides with Amines and Effects of Br?nsted Acids in Quinuclidine-Catalyzed Halocyclizations
Li, Jing,Kwon, Eunsang,Lear, Martin J.,Hayashi, Yujiro
, (2021/08/09)
An arguable expectation in halogen chemistry is that an amine will react oxidatively with an N-halosuccinimide (NXS) to form an N-halogenated species bearing a covalent N?X bond. While likely for NCS under most conditions, we find this expectation simply
Directed Copper-Catalyzed Intermolecular Aminative Difunctionalization of Unactivated Alkenes
Li, Yang,Liang, Yujie,Dong, Junchao,Deng, Yi,Zhao, Chunyang,Su, Zhongmin,Guan, Wei,Bi, Xihe,Liu, Qun,Fu, Junkai
supporting information, p. 18475 - 18485 (2019/11/19)
A diverse collection of copper-catalyzed intermolecular aminative difunctionalizations of unactivated alkenes with N-halodialkylamines as the terminal dialkylamino source is reported. A bidentate auxiliary tethered on the alkene substrates is crucial, which can promote the migratory insertion of nonactivated alkenes into the aminyl radical-metal complex and stabilize the resultant high-valent copper intermediate to allow for further transformations. By employing this strategy, the intermolecular aminohalogenation reactions and a three-component aminoazidation reaction of unactivated alkenes with dialkylamino source were successively achieved in a remarkable regio- and stereoselective manner. These reactions were performed under neutral conditions and maintained excellent functional group tolerance toward a wide range of N-halodialkylamines and unactivated alkenes. Further mechanistic studies and DFT calculations supported a concerted migratory insertion of the C-C double bond into the aminyl radical-metal complex to form a Cu(III) intermediate.
Mechanism of Oxidative Amidation of Nitroalkanes with Oxygen and Amine Nucleophiles by Using Electrophilic Iodine
Li, Jing,Lear, Martin J.,Kwon, Eunsang,Hayashi, Yujiro
supporting information, p. 5538 - 5542 (2016/04/20)
Recently, we developed a direct method to oxidatively convert primary nitroalkanes into amides that entailed mixing an iodonium source with an amine, base, and oxygen. Herein, we systematically investigated the mechanism and likely intermediates of such methods. We conclude that an amine-iodonium complex first forms through N-halogen bonding. This complex reacts with aci-nitronates to give both α-iodo- and α,α-diiodonitroalkanes, which can act as alternative sources of electrophilic iodine and also generate an extra equimolar amount of I+ under O2. In particular, evidence supports α,α-diiodonitroalkane intermediates reacting with molecular oxygen to form a peroxy adduct; alternatively, these tetrahedral intermediates rearrange anaerobically to form a cleavable nitrite ester. In either case, activated esters are proposed to form that eventually reacts with nucleophilic amines in a traditional fashion.
Reactions of N-Halogenobenzylmethylamines with Triethylamine in Acetonitrile. Effect of Leaving Group upon the Imine-forming Transition State
Cho, Bong Rae,Namgoong, Sung Keon,Kim, Tae Rin
, p. 853 - 856 (2007/10/02)
Reactions of N-halogenobenzylmethylamines (1) and (2) with Et3N-MeCN have been investigated kinetically.Eliminations from (1) and (2) were quantitative and regiospecific, producing only benzylidenemethylamines.For the elimination reaction of (1) with Et3N, kH/kD 5.7, ρ 0.88, 9.1 kcal mol-1, and -42.4 cal mol-1 K-1 were determined.The transition-state structure is assessed as being highly symmetric with similar extents of Cβ-H and Nα-Cl bond cleavage, little carbanionic character, and significant ?-bond formation.The structure of the transition state changes only slightly with the change in the leaving group from Cl to Br.
