21386-74-3Relevant academic research and scientific papers
Copper-Catalyzed Oxidative Benzylic C(sp3)?H Cyclization for the Synthesis of β-Lactams
Nozawa-Kumada, Kanako,Saga, Satoshi,Matsuzawa, Yuta,Hayashi, Masahito,Shigeno, Masanori,Kondo, Yoshinori
supporting information, p. 4496 - 4499 (2020/04/10)
β-Lactams are important structural motifs because of their ubiquity in natural products and pharmaceuticals. We report herein a Cu-catalyzed intramolecular oxidative C(sp3)?H amidation for the synthesis of β-lactams using tBuOOtBu. This method
Chemical-Reductant-Free Electrochemical Deuteration Reaction using Deuterium Oxide
Cheng, Xu,Li, Guigen,Liu, Ruoyu,Liu, Xu,Qiu, Jiaxing
supporting information, p. 13962 - 13967 (2020/06/10)
We report a method for the electrochemical deuteration of α,β-unsaturated carbonyl compounds under catalyst- and external-reductant-free conditions, with deuteration rates as high as 99 percent and yields up to 91 percent in 2 h. The use of graphite felt for both the cathode and the anode was key to ensuring chemoselectivity and high deuterium incorporation under neutral conditions without the need for an external reductant. This method has a number of advantages over previously reported deuteration reactions that use stoichiometric metallic reductants. Mechanistic experiments showed that O2 evolution at the anode not only eliminates the need for an external reductant but also regulates the pH of the reaction mixture, keeping it approximately neutral.
Cyclohexyl-Fused, Spirobiindane-Derived, Phosphine-Catalyzed Synthesis of Tricyclic ?3-Lactams and Kinetic Resolution of ?3-Substituted Allenoates
Wu, Mingyue,Han, Zhaobin,Li, Kaizhi,Wu, Ji'En,Ding, Kuiling,Lu, Yixin
supporting information, p. 16362 - 16373 (2019/10/16)
A C2-symmetric chiral phosphine catalyst, NUSIOC-Phos, which can be easily derived from cyclohexyl-fused spirobiindane, was introduced. A highly enantioselective domino process involving pyrrolidine-2,3-diones and γ-substituted allenoates catalyzed by NUSIOC-Phos has been disclosed. Diastereospecific tricyclic γ-lactams containing five contiguous stereogenic centers were obtained in high yields and with nearly perfect enantioselectivities. A kinetic resolution process of racemic γ-substituted allenoates was developed for the generation of optically enriched chiral allenoates.
Remote sp3 C–H Amination of Alkenes with Nitroarenes
Xiao, Jichao,He, Yuli,Ye, Feng,Zhu, Shaolin
supporting information, p. 1645 - 1657 (2018/05/16)
Direct installation of a functional group at remote, unfunctionalized sites in an alkyl chain is a synthetically valuable but rarely reported process. The remote relay hydroarylamination of distal and proximal olefins, and of olefin isomeric mixtures, has been achieved through NiH-catalyzed alkene isomerization and sequential reductive hydroarylamination with nitroarenes. This provides an attractive approach to the direct installation of a distal arylamino group within alkyl chains. The single-step conversion of simple olefins and nitro(hetero)arenes to value-added arylamines is a practical strategy for amine synthesis as well as the remote activation of sp3 C–H bonds. The value of this transformation is further supported by the regioconvergent arylamination of isomeric mixtures of olefins. Modern organic synthesis requires more efficient strategies, such as C–H functionalization, with which to construct complex molecules from readily available chemicals. Undirected functionalization of remote aliphatic C–H bonds is a synthetically valuable but largely unknown process. Synergistic combination of metal-catalyzed chainwalking (migration of a double bond along the hydrocarbon chain, a process involving repeated migratory insertions and β-hydride eliminations) and cross-coupling chemistry offers a general approach to the remote functionalization of easily accessed unsaturated hydrocarbon substrates. In this paper, we demonstrate that direct installation of a distal arylamino group can be achieved from two common feedstock chemicals (olefins and nitroarenes) via nickel hydride chemistry. It is anticipated that the strategy could inspire the development of other remote functionalizations with different regioselectivity as well as asymmetric transformations. Zhu and colleagues describe the remote hydroamination of alkenes with nitro(hetero)arenes through nickel-catalyzed alkene isomerization and sequential reductive relay hydroamination process. Using two common feedstock chemicals, olefins and nitroaromatics, in an operationally simple procedure, this attractive protocol provides efficient and practical access to a wide range of arylamines under mild conditions.
Ambulation of Incipient Proton during Gas-Phase Dissociation of Protonated Alkyl Dihydrocinnamates
Xu, Sihang,Zhang, Yong,Errabelli, Ramu,Attygalle, Athula B.
, p. 9468 - 9479 (2015/10/12)
Upon activation in the gas phase, protonated alkyl dihydrocinnamates undergo an alcohol loss. However, the mechanism followed is not a simple removal of an alkanol molecule after a protonation on the alkoxy group. The mass spectrum of the m/z 166 ion for deuteron-charged methyl dihydrocinnamate showed two peaks of 1:5 intensity ratio at m/z 133 and 134 to confirm that the incipient proton is mobile. The proton initially attached to the carbonyl group migrates to the ring and randomizes before a subsequent transfer of one of the ring protons to the alkoxy group for the concomitant alcohol elimination. Moreover, protonated methyl dihydrocinnamate undergoes more than one H/D exchange. The spectra recorded from m/z 167 and 168 ions obtained for di- and tri-deuterio isotopologues showed peak pairs at m/z 134, 135 and 135, 136, at 1:2 and 1:1 intensity ratios, respectively, confirming the benzenium ion intermediate achieves complete randomization before the proton transfer. Additionally, protonated higher esters of alkyl dihydrocinnamates undergo a cleavage of the O-CH2 bond to form an ion/neutral complex, which, upon activation, dissociates generating a carbenium ion and dihydrocinnamic acid, or rearranges to generate protonated dihydrocinnamic acid and an alkene by a nonspecific proton transfer.
A convenient method for palladium-catalyzed reductive deuteration of organic substrates using deuterated hypophosphite in D2O
Oba, Makoto
, p. 215 - 219 (2015/05/20)
A convenient method for the deuteration of organic substrates using deuterated hypophosphite as the deuterium source was investigated. Transfer deuteration of organic substrates, such as aromatic halides, alkenes, alkynes, epoxides, and O-benzyl derivativ
Facile and convenient method of deuterium gas generation using a Pd/C-catalyzed H2-D2 exchange reaction and itsapplication to synthesis of deuterium-labeled compounds
Kurita, Takanori,Aoki, Fumiyo,Mizumoto, Takuto,Maejima, Toshihide,Esaki, Hiroyoshi,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
scheme or table, p. 3371 - 3379 (2009/04/10)
The Pd/C-catalyzed H2-D2 exchange reaction using a H2-D2O combination provided a general, efficient and environmentally friendly route for the preparation of deuterium gas (D 2). H2 sealed
Deuteration of α,β-acetylenic esters, amides, or carboxylic acids without using deuterium gas: Synthesis of 2,2,3,3-tetradeuterioesters, amides, or acids
Concellón, José M.,Rodríguez-Solla, Humberto,Concellón, Carmen
, p. 2129 - 2131 (2007/10/03)
An easy, simple, rapid, and nonhazardous deuteration of the C-C triple bond of α,β-acetylenic esters, amides, or acids by means of samarium diiodide in the presence of D2O, provides an efficient method for synthesizing 2,2,3,3-tetradeuterioesters, amides, or carboxylic acids, respectively. When H2O is used instead of D2O, saturated carboxylic esters, amides, or acids were isolated. A mechanism to explain these reduction reactions has been proposed.
