699-01-4Relevant academic research and scientific papers
Enantioselective Resolution Copolymerization of Racemic 2,3-Disubstituted cis-Epoxides with CO2 Mediated by Binuclear Cobalt(III) Catalyst?
He, Guang-Hui,Liu, Yan-Lan,Liu, Ye,Lu, Xiao-Bing
, p. 2386 - 2390 (2021/07/12)
Enantioselective resolution copolymerization of racemic internal epoxides with carbon dioxide (CO2) is a challenging issue because of their poor reactivity and complicated regio/stereoselectivity. Herein, we describe the first enantioselective
Bifunctional Metal-Organic Layers for Tandem Catalytic Transformations Using Molecular Oxygen and Carbon Dioxide
Jiang, Xiaomin,Lan, Guangxu,Lin, Wenbin,Ni, Kaiyuan,Quan, Yangjian,Shi, Wenjie,Song, Yang,Wang, Cheng
supporting information, p. 16718 - 16724 (2021/10/21)
Tandem catalytic reactions improve atom- and step-economy over traditional synthesis but are limited by the incompatibility of the required catalysts. Herein, we report the design of bifunctional metal-organic layers (MOLs), HfOTf-Fe and HfOTf-Mn, consisting of triflate (OTf)-capped Hf6 secondary building units (SBUs) as strong Lewis acidic centers and metalated TPY ligands as metal active sites for tandem catalytic transformations using O2 and CO2 as coreactants. HfOTf-Fe effectively transforms hydrocarbons into cyanohydrins via tandem oxidation with O2 and silylcyanation whereas HfOTf-Mn converts styrenes into styrene carbonates via tandem epoxidation and CO2 insertion. Density functional theory calculations revealed the involvement of a high-spin FeIV (S = 2) center in the challenging oxidation of the sp3 C-H bond. This work highlights the potential of MOLs as a tunable platform to incorporate multiple catalysts for tandem transformations.
Synthesis of Substituted β-Functionalised Styrenes by Microwave-Assisted Olefin Cross-Metathesis and Scalable Synthesis of Apremilast
Jana, Anupam,Zieliński, Grzegorz Krzysztof,Czarnocka-?niada?a, Sylwia,Grudzień, Krzysztof,Podwysocka, Dominika,Szulc, Marcin,Kajetanowicz, Anna,Grela, Karol
, p. 5808 - 5813 (2019/11/03)
Preparation of diversely substituted β-functionalised styrenes by microwave-assisted olefin cross-metathesis (CM) is described. This method can be also employed in the synthesis of β-deuterated α,β-unsaturated sulfones from inexpensive allylbenzenes, though unprecedented one-pot isomerisation/deuteration/cross-metathesis sequence. One of such obtained CM products has been utilised in a new scalable synthesis of Apremilast (6), a potent and orally active phosphodiesterase 4 and tumour necrosis factor-α inhibitor. The same strategy was used in synthesis of an optical antipode of 6, ent-Apremilast.
Visible photocatalysis of novel oxime phosphonates: Synthesis of β-aminophosphonates
Li, Yong-Hong,Wang, Chun-Hai,Gao, Su-Qian,Qi, Feng-Ming,Yang, Shang-Dong
supporting information, p. 11888 - 11891 (2019/10/11)
A novel type of oxime phosphonate was synthesized and used in the intermolecular cascade radical addition reaction of alkenes to access β-aminophosphonates via visible-light-driven N-centered iminyl radical-mediated and redox-neutral selective C-P single-bond cleavage in an active phosphorus radical route. The procedure is characterized by its ability to achieve the construction of Csp3-P and Csp3-N bonds without the requirement for oxidants and bases.
Alkene functionalization for the stereospecific synthesis of substituted aziridines by visible-light photoredox catalysis
Yu, Wan-Lei,Chen, Jian-Qiang,Wei, Yun-Long,Wang, Zhu-Yin,Xu, Peng-Fei
supporting information, p. 1948 - 1951 (2018/03/01)
A novel strategy involving visible-light-induced functionalization of alkenes for the synthesis of substituted aziridines was developed. The readily prepared N-protected 1-aminopyridinium salts were used for the generation of N-centered radicals. This approach allowed the synthesis of aziridines bearing various functional groups with excellent diastereoselectivity under mild conditions. Moreover, this protocol was successfully applied to prepare structurally diverse nitrogen-containing frameworks.
Visible-light-mediated anti-regioselective nitrone 1, 3-dipolar cycloaddition reaction and synthesis of bisindolylmethanes
Zheng, Lewei,Gao, Fei,Yang, Chao,Gao, Guo-Lin,Zhao, Yating,Gao, Yuan,Xia, Wujiong
supporting information, p. 5086 - 5089 (2017/11/07)
The development of photoredox reactions of 1, 3- dipolar cycloaddition of nitrones with alkenes is reported. It offers an efficient synthetic method to obtain isoxazolidine derivatives under mild conditions in synthetically useful yields. The nitrones are cyclized with oxidizable styrenes and aliphatic alkenes via a polar radical crossover cycloaddition reaction through photocatalytic reaction without additives. In addition, bis(indole)methanes can also be prepared through this method.
Practical iron-catalyzed allylations of aryl grignard reagents
Mayer, Matthias,Czaplik, Waldemar M.,Von Wangelin, Axel Jacobi
supporting information; experimental part, p. 2147 - 2152 (2010/12/18)
An operationally simple iron-catalyzed reductive cross-coupling reaction between aryl halides and allyl electrophiles has been developed. The underlying domino process exhibits high versatility with respect to the allylic leaving group (acetate, tosylate, diethyl phosphate, methyl carbonate, trimethylsilanolate, methanethiolate, chloride, bromide) and high economic and environmental sustainability with respect to the catalyst system (0.2-5 mol% tris(acetylacetonato)iron(III), ligand-free) and reaction conditions (tetrahydrofuran, 0°C, 45 min).
Nickel catalyzed cross-coupling of modified alkyl and alkenyl Grignard reagents with aryl- and heteroaryl nitriles: Activation of the C-CN bond
Miller, Joseph A.,Dankwardt, John W.
, p. 1907 - 1910 (2007/10/03)
The nickel catalyzed cross-coupling of alkyl and alkenyl Grignard reagents with aryl nitrile derivatives affords good yields of the corresponding aryl alkanes or aryl alkenes via activation of the C-CN bond. To prevent direct addition of the nucleophile to the nitrile group, the reactivity of the Grignard reagent was modulated by reaction with either LiOt-Bu or PhSLi prior to cross-coupling. The optimum catalyst was determined to be NiCl2(PMe3)2, which is a convenient air stable commercially available complex.
