66897-25-4Relevant academic research and scientific papers
Electrochemical oxidative cyclization of: N -allylcarboxamides: Efficient synthesis of halogenated oxazolines
He, Yanyang,Liu, Chenwei,Wu, Xiao-Feng,Yin, Yanzhao,Yin, Zhiping
supporting information, p. 663 - 667 (2022/01/22)
Herein, we reported an efficient and sustainable intramolecular electrochemical cyclization of N-allylcarboxamides for the synthesis of various halogenated oxazolines. This method was conducted in a simple undivided cell by employing lithium halogen salts
Stereoselective Oxidative Cyclization ofN-Allyl Benzamides to Oxaz(ol)ines
Abazid, Ayham H.,Hollwedel, Tom-Niklas,Nachtsheim, Boris J.
supporting information, p. 5076 - 5080 (2021/07/19)
This study presents an enantioselective oxidative cyclization ofN-allyl carboxamides via a chiral triazole-substituted iodoarene catalyst. The method allows the synthesis of highly enantioenriched oxazolines and oxazines, with yields of up to 94% and enantioselectivities of up to 98% ee. Quaternary stereocenters can be constructed and, besidesN-allyl amides, the corresponding thioamides and imideamides are well tolerated as substrates, giving rise to a plethora of chiral 5-memberedN-heterocycles. By applying a multitude of further functionalizations, we finally demonstrate the high value of the observed chiral heterocycles as strategic intermediates for the synthesis of other enantioenriched target structures.
A Next-Generation Air-Stable Palladium(I) Dimer Enables Olefin Migration and Selective C?C Coupling in Air
Kundu, Gourab,Rissanen, Kari,Schoenebeck, Franziska,Sperger, Theresa
supporting information, p. 21930 - 21934 (2020/10/02)
We report a new air-stable PdI dimer, [Pd(μ-I)(PCy2tBu)]2, which triggers E-selective olefin migration to enamides and styrene derivatives in the presence of multiple functional groups and with complete tolerance of air. The same dimer also triggers extremely rapid C?C coupling (alkylation and arylation) at room temperature in a modular and triply selective fashion of aromatic C?Br, C?OTf/OFs, and C?Cl bonds in poly(pseudo)halogenated arenes, displaying superior activity over previous PdI dimer generations for substrates that bear substituents ortho to C?OTf.
Sequential catalytic carbonylation reactions for sustainable synthesis of biologically relevant entities
Carrilho, Rui M. B.,Damas, Liliana,Gonzalez, Andreia C. S.,Pereira, Mariette M.,Pineiro, Marta,Rodrigues, Fábio M. S.
, (2020/07/31)
The sustainable synthesis of highly functionalised formylcarboxamide compounds with biological relevance is reported through a sequential aminocarbonylation/hydroformylation approach. The optimisation of palladium-catalysed aminocarbonylation of iodoaromatic substrates, using allylamine as nucleophile was first performed, with molybdenum hexacarbonyl as alternative CO source versus gaseous carbon monoxide. The combination of microwave irradiation with molybdenum hexacarbonyl allowed to selectively prepare a set of N-heterocyclic-based allylcarboxamides. Subsequent rhodium-catalysed hydroformylation of the allylcarboxamide intermediates led to the preparation of new pyridine, pyrazoline and chalcone derivatives containing both carboxamide and formyl moieties.
Electrochemical Chalcogenation of β,γ-Unsaturated Amides and Oximes to Corresponding Oxazolines and Isoxazolines
Baidya, Mrinmay,De Sarkar, Suman,Mahanty, Kingshuk,Maiti, Debabrata,Mallick, Samrat
supporting information, (2020/02/04)
The current report represents a transition-metal-free synthesis of oxazoline and isoxazoline derivatives by a tandem electro-oxidative chalcogenation-cyclization process. Both C?Se and C?S bond-forming protocols were developed without using any external oxidant and the reaction was performed at room temperature, open to the air. Using this methodology, 29 substituted oxazoline and 16 substituted isoxazoline derivatives were synthesized with up to 91% isolated yield. (Figure presented.).
Preparation of Heterocycles via Visible-Light-Driven Aerobic Selenation of Olefins with Diselenides
Zhang, Qing-Bao,Yuan, Pan-Feng,Kai, Liang-Lin,Liu, Kai,Ban, Yong-Liang,Wang, Xue-Yang,Wu, Li-Zhu,Liu, Qiang
supporting information, p. 885 - 889 (2019/02/14)
The aerobic dehydrogenative cyclization of alkenes with easily accessible diselenides facilitated by visible light is reported. Notably, the features of this transition-metal-free protocol are pronounced efficiency and practicality, good functional group
Electrochemical oxidative cyclization of olefinic carbonyls with diselenides
Guan, Zhipeng,Wang, Yunkun,Wang, Huamin,Huang, Yange,Wang, Siyuan,Tang, Hongding,Zhang, Heng,Lei, Aiwen
supporting information, p. 4976 - 4980 (2019/09/30)
The tandem cyclization of olefinic carbonyls with easily accessible diselenides facilitated by electrochemical oxidation has been successfully developed, which provides an environmentally friendly method for the construction of C-Se and C-O bonds simultaneously. A series of seleno dihydrofurans and seleno oxazolines, bearing fragile heterocycles, subtle C-I bonds and supernumerary vinyl groups, were forged using this elegant chelation strategy. Neither metal catalysts nor external chemical oxidants are required to promote this transformation.
Electrochemical Fluorocyclization of N-Allylcarboxamides to 2-Oxazolines by Hypervalent Iodine Mediator
Haupt, John D.,Berger, Michael,Waldvogel, Siegfried R.
supporting information, p. 242 - 245 (2019/01/04)
A resource saving protocol for the synthesis of 5-fluoromethyl-2-oxazolines by using electrochemistry has been realized. Thereby, a hypervalent iodine species I(III) is generated by anodic oxidation in the presence of Et3N·5HF and mediates the
Silver-Promoted Synthesis of 5-[(Pentafluorosulfanyl)methyl]-2-oxazolines
Gilbert, Audrey,Bertrand, Xavier,Paquin, Jean-Fran?ois
supporting information, p. 7257 - 7260 (2018/11/23)
The synthesis of 5-[(pentafluorosulfanyl)methyl]-2-oxazolines is reported. The use of a silver promoter allows the intramolecular cyclization of N-[2-chloro-3-(pentafluorosulfanyl)propyl]amide to occur without elimination of the chlorine atom, a reaction
Fluorocyclisation via I(I)/I(III) catalysis: A concise route to fluorinated oxazolines
Daniliuc, Constantin G.,Gilmour, Ryan,Kehr, Gerald,Meyer, Stephanie,Scheidt, Felix,Thiehoff, Christian,Yilmaz, Gülay
supporting information, p. 1021 - 1027 (2020/05/06)
Herein, we describe a catalytic fluorooxygenation of readily accessible N-allylcarboxamides via an I(I)/I(III) manifold to generate 2-oxazolines containing a fluoromethyl group. Catalysis is conditional on the oxidation competence of Selectfluor, whilst HF serves as both a fluoride source and Br?nsted acid activator. The C(sp3)–F bond of the mono-fluoromethyl unit and the C(sp3)–O bond of the ring are aligned in a synclinal relationship thereby engaging in stabilising hyperconjugative interactions with vicinal, electron-rich σ-bonds (σC–C→σ*C–F and σC–H→σ*C–O). This manifestation of the stereoelectronic gauche effect was established by X-ray crystallographic analysis of a representative example. Given the importance of fluorine in drug discovery, its ability to modulate conformation, and the prevalence of the 2-oxazoline scaffold in Nature, this strategy provides a rapid entry into an important bioisostere class.
