35003-56-6Relevant academic research and scientific papers
Enantioselective Reductive Coupling of Imines Templated by Chiral Diboron
Chen, Dongping,Li, Kaidi,Tang, Wenjun,Xu, Guangqing,Xu, Ronghua,Zhou, Mingkang
supporting information, p. 10337 - 10342 (2020/07/04)
We herein report a general, practical, and highly efficient method for asymmetric synthesis of a wide range of chiral vicinal diamines via reductive coupling of imines templated by chiral diboron. The protocol features high enantioselectivity and stereospecificity, mild reaction conditions, simple operating procedures, use of readily available starting materials, and a broad substrate scope. The method signifies the generality of diboron-enabled [3,3]-sigmatropic rearrangement.
Stable carbamate pathway towards organic-inorganic hybrid perovskites and aromatic imines
Hur, Nam Hwi,Kim, Sun Joo,Lee, Byeongno,Lee, Kyu Hyung,Lim, Byung Wook,Nam, Wonwoo,Park, Hee Sun,Park, Young Jun
, p. 38055 - 38062 (2020/11/02)
Methyl ammonium methyl carbamate (MAC), formulated as CH3NH3+CH3NHCO2-, was synthesized by reacting liquid methylamine with supercritical CO2, and its structure was refined by single-crystal X-ray diffraction. MAC is a white crystalline salt and is as reactive as methylamine, and is a very efficient alternative to toxic methylamine. We were able to produce hybrid perovskite MAPbI3 (MA = methyl ammonium) by grinding MAC with PbI2 and I2 at room temperature, followed by storing the mixed powder. Moreover, this one-pot method is easily scalable for the large-scale synthesis of MAPbI3 in a small vessel. We have also investigated the reactivity of MAC towards aromatic aldehydes in the absence of solvent. The solventless reactions afforded imines as exclusive products with over 97% yield, which show higher selectivity than the methylamine-based synthesis. Complete conversions were typically accomplished within 3 h at 25 °C. The results of this study emphasize the importance of solid carbamates such as MAC to develop an environmentally friendly process for the synthesis of various amine-based materials on the industrial scale.
Stereocomplementary Synthesis of cis- and trans-2-(p-Bromophenyl)-5-methylthiazolidin-4-ones: Useful Umpolung-type Suzuki–Miyaura Cross-coupling Partner and Donor
Sasaki, Ryosuke,Nakatsuji, Hidefumi,Tanabe, Yoo
, p. 1112 - 1118 (2018/03/21)
Novel cis- and trans-2-(p-bromophenyl)-5-methylthiazolidin-4-ones, S,N-containing heterocyclic compounds, were provided in a cis-stereocomplementary and trans-stereocomplementary synthetic manner. cis-Selective cyclo-condensation proceeded between 2-sulfanylpropanoic acid (thiolactic acid) and an imine derived from 4-bromobenzaldehyde and methylamine, whereas Ti(OiPr)4 and Ti(OiBu)4-promoted trans-selective cyclo-condensation proceeded between benzyl 2-sulfanylpropanoate and the imine. The obtained cis- and trans-2-(p-bromophenyl)-5-methylthiazolidin-4-ones were successfully converted to 2-(3-furyl)phenyl derivatives and bis(pinacolato)diborane derivatives utilizing Suzuki–Miyaura and Miyaura–Ishiyama cross-coupling reactions, respectively, in an umpolung manner.
Cooperative Multifunctional Catalysts for Nitrone Synthesis: Platinum Nanoclusters in Amine-Functionalized Metal–Organic Frameworks
Li, Xinle,Zhang, Biying,Tang, Linlin,Goh, Tian Wei,Qi, Shuyan,Volkov, Alexander,Pei, Yuchen,Qi, Zhiyuan,Tsung, Chia-Kuang,Stanley, Levi,Huang, Wenyu
supporting information, p. 16371 - 16375 (2017/11/28)
Nitrones are key intermediates in organic synthesis and the pharmaceutical industry. The heterogeneous synthesis of nitrones with multifunctional catalysts is extremely attractive but rarely explored. Herein, we report ultrasmall platinum nanoclusters (PtNCs) encapsulated in amine-functionalized Zr metal–organic framework (MOF), UiO-66-NH2 (Pt@UiO-66-NH2) as a multifunctional catalyst in the one-pot tandem synthesis of nitrones. By virtue of the cooperative interplay among the selective hydrogenation activity provided by the ultrasmall PtNCs and Lewis acidity/basicity/nanoconfinement endowed by UiO-66-NH2, Pt@UiO-66-NH2 exhibits remarkable activity and selectivity, in comparison to Pt/carbon, Pt@UiO-66, and Pd@UiO-66-NH2. Pt@UiO-66-NH2 also outperforms Pt nanoparticles supported on the external surface of the same MOF (Pt/UiO-66-NH2). To our knowledge, this work demonstrates the first examples of one-pot synthesis of nitrones using recyclable multifunctional heterogeneous catalysts.
Four-Electron Electrocyclic Ring-Opening/Intermolecular [4+2] Cycloadditions of α-Hydroxycyclobutenones: Stereoselective Synthesis of Multiple Substituted δ-Lactams
Song, Peidong,Li, Qing,Wang, Congcong,Wu, Wenfa,Mao, Xu,Wang, Jiajia,Hu, Xiangdong
supporting information, p. 1208 - 1212 (2016/04/26)
A four-electron electrocyclic ring-opening/intermolecular [4+2] cycloaddition of α-hydroxycyclobutenones is reported. The reaction represents the first example for the intermolecular cycloaddition of the extensively studied enol-ketene intermediate, and provides a new synthetic route to multiply substituted δ-lactams in high stereoselectivity.
Asymmetric synthesis of tetrahydropyridines via an organocatalytic one-pot multicomponent Michael/aza-Henry/cyclization triple domino reaction
Blümel, Marcus,Chauhan, Pankaj,Hahn, Robert,Raabe, Gerhard,Enders, Dieter
supporting information, p. 6012 - 6015 (2015/01/08)
A low loading of a quinine-derived squaramide efficiently catalyzes the triple-domino Michael/aza-Henry/cyclization reaction between 1,3-dicarbonyl compounds, β-nitroolefins, and aldimines to provide tetrahydropyridines bearing three contiguous stereogeni
Cobalt-catalyzed cyclization of carbon monoxide, imine, and epoxide
Zhang, Yubo,Ji, Jiamin,Zhang, Xiuliang,Lin, Shaohui,Pan, Qinmin,Jia, Li
supporting information, p. 2130 - 2133 (2014/05/06)
Cobalt-catalyzed cyclization of CO, imine, and epoxide has been developed. A convenient catalyst system composed of Co2(CO)8 and LiCl is identified, and the substrate scope has been explored. The reaction provides an efficient method for the synthesis of substituted 1,3-oxazinan-4-ones.
A latent reaction in a model GFP chromophore revealed upon confinement: Photohydroxylation of ortho -halo benzylidene-3-methylimidazolidiones via an electrocylization process
Samanta, Shampa R.,Da Silva, Jose P.,Baldridge, Anthony,Tolbert, Laren M.,Ramamurthy
supporting information, p. 3304 - 3307 (2014/07/08)
Excited state behavior of halogen substituted model GFP chromophores was investigated in an acetonitrile solution and in a confined environment provided by an octa acid capsule in water. Of the ortho, meta, and para halogen substituted GFP chromophores on
Chemoselective reductive nucleophilic addition to tertiary amides, secondary amides, and N-methoxyamides
Nakajima, Minami,Oda, Yukiko,Wada, Takamasa,Minamikawa, Ryo,Shirokane, Kenji,Sato, Takaaki,Chida, Noritaka
supporting information, p. 17565 - 17571 (2015/02/19)
As the complexity of targeted molecules increases in modern organic synthesis, chemoselectivity is recognized as an important factor in the development of new methodologies. Chemoselective nucleophilic addition to amide car-bonyl centers is a challenge because classical methods require harsh reaction conditions to overcome the poor elec-trophilicity of the amide carbonyl group. We have successfully developed a reductive nucleophilic addition of mild nu-cleophiles to tertiary amides, secondary amides, and N-methoxyamides that uses the Schwartz reagent [Cp2ZrHCl]. The reaction took place in a highly chemoselective fashion in the presence of a variety of sensitive functional groups, such as methyl esters, which conventionally require protection prior to nucleophilic addition. The reaction will be applicable to the concise synthesis of complex natural alkaloids from readily available amide groups.
Simple and efficient one-pot solvent-free synthesis of N-methyl imines of aromatic aldehydes
Radulovi?, Niko S.,Miltojevi?, Ana B.,Vuki?evi?, Rastko D.
, p. 257 - 270 (2013/05/09)
A one-pot solvent-free synthesis of N-methyl imines in good to excellent yields was performed by grinding together aromatic aldehydes and methylamine hydrochloride in the presence of a base. The best yields were achieved when an excess of methylamine hydrochloride and inexpensive sodium hydrogen carbonate was used (usually in a molar ratio ArCHO/CH3NH2· HCl/NaHCO3 = 1:5:5), allowing the reaction to proceed for 1 h (in the case of aromatic aldehydes containing electron-withdrawing substituents) or overnight (in the case of electron-rich aldehydes). After a simple work-up (extraction with diethyl ether) the obtained products were mostly pure enough for spectral characterization. In this way, 31 N-methyl imines were prepared, among which eight were synthesized for the first time. Their structures were elucidated by spectral means (1H- and 13C-NMR, IR, MS) whenever it was possible. In the case of salicylaldehyde and 4-chlorobenzaldehyde, the synthesis of the corresponding imines was also conducted on a gram-scale with a 72% and 84% isolated yield, respectively. The present approach not only provides good to high yields, but also eliminates the disadvantages of the traditional synthesis of N-methyl imines, such as the use of hazardous solvents and more or less expensive catalysts and the necessity of work/handling with an anhydrous gas in pressurized containers.
