53416-46-9Relevant articles and documents
Preparation of Polyfunctionalized Aromatic Nitriles from Aryl Oxazolines
Hess,Guelen,Alandini,Mourati,Guersoy,Knochel
, (2021/12/06)
A selective ortho,ortho’-functionalization of readily available aryl oxazolines by two successive magnesiations with sBu2Mg in toluene followed by trapping reactions with electrophiles, such as (hetero)aryl iodides or bromides, iodine, tosyl cyanide, ethyl cyanoformate or allylic bromides (39 examples, 62–99 % yield) is reported. Treatment of these aryl oxazolines with excess oxalyl chloride and catalytic amounts of DMF (50 °C, 4 h) provided the corresponding nitriles (36 examples, 73–99 % yield). Conversions of these nitriles to valuable heterocycles are reported, and a tentative mechanism is proposed.
Substitution Effect on 2-(Oxazolinyl)-phenols and 1,2,5-Chalcogenadiazole -Annulated Derivatives: Emission-Color-Tunable, Minimalistic Excited-State Intramolecular Proton Transfer (ESIPT)-Based Luminophores
G?bel, Dominik,Rusch, Pascal,Duvinage, Daniel,Stauch, Tim,Bigall, Nadja-C.,Nachtsheim, Boris J.
supporting information, p. 14333 - 14355 (2021/10/20)
Minimalistic 2-(oxazolinyl)-phenols substituted with different electron-donating and -withdrawing groups as well as 1,2,5-chalcogenadiazole-annulated derivatives thereof were synthesized and investigated in regard to their emission behavior in solution as well as in the solid state. Depending on the nature of the incorporated substituent and its position, emission efficiencies were increased or diminished, resulting in AIE or ACQ characteristics. Single-crystal analysis revealed J- and H-type packing motifs and a so-far undescribed isolation of ESIPT-based fluorophores in the keto form.
Aerobic C(sp2)-H Hydroxylations of 2-Aryloxazolines: Fast Access to Excited-State Intramolecular Proton Transfer (ESIPT)-Based Luminophores
G?bel, Dominik,Clamor, Nils,Lork, Enno,Nachtsheim, Boris J.
supporting information, p. 5373 - 5377 (2019/06/07)
The direct hydroxylation of 2-aryloxazolines via a deprotonative magnesiation using TMPMgCl·LiCl and subsequent oxidation with molecular oxygen or air as a green oxidant is reported. This method proceeds under mild conditions at room temperature with high regioselectivity and chemoselectivity. The obtained phenols exhibit tunable luminescence properties, induced by excited-state intramolecular proton transfer. This method opens a new opportunity for the sustainable synthesis of luminescent organic molecules.
Palladium-catalyzed direct C2-arylation of azoles with aromatic triazenes
Liu, Can,Wang, Zhiming,Wang, Lei,Li, Pinhua,Zhang, Yicheng
, p. 9209 - 9216 (2019/11/05)
A highly efficient palladium-catalyzed arylation of azoles at the C2-position using 1-aryltriazenes as aryl reagents was developed. Azoles including oxazoles, thiazoles, imidazoles, 1,3,4-oxadiazoles, and oxazolines could react with 1-aryltriazenes smoothly to generate the corresponding products in good to excellent yields, and various substitution patterns were tolerated toward the reaction.
Synthesis of asymmetrically disubstituted anthracenes
?kalamera, ?ani,Veljkovi?, Jelena,Pti?ek, Lucija,Sambol, Matija,Mlinari?-Majerski, Kata,Basari?, Nikola
supporting information, p. 5892 - 5899 (2017/09/09)
We have developed synthetic pathways toward differently substituted hydroxyanthracenes (anthrols) with the aim to investigate their photochemical reactivity in dehydration reactions. Although the syntheses of anthracenes substituted at positions 9,10 are well known, reports for the synthesis of anthracenes with different substitution patterns are scarce. Herein we review known and report novel synthetic pathways toward anthrols with substituents at 1,2-, 2,3-, and 2,6- positions. We present two synthetic approaches: (i) building of the anthracene tricyclic fused ring system from the appropriate benzene derivatives, and (ii) reduction of the corresponding anthraquinones. Reduction of 2-hydroxyanthracene-1-carbaldehyde to the corresponding alcohol yields rather unexpected 1,1′-methylenedianthracen-2-ol, whose proposed mechanism of formation is supported by experimental observations and calculations.
Secondary Phosphine Oxide Preligands for Palladium-Catalyzed C–H (Hetero)Arylations: Efficient Access to Pybox Ligands
Ghorai, Debasish,Müller, Valentin,Keil, Helena,Stalke, Dietmar,Zanoni, Giuseppe,Tkachenko, Boryslav A.,Schreiner, Peter R.,Ackermann, Lutz
supporting information, p. 3137 - 3141 (2017/09/06)
C–H arylations of oxazolines were accomplished with a well-defined palladium catalyst derived from a secondary bisdiamantyl phosphine oxide. The single-component secondary phosphine oxide (SPO)-palladium complex enabled C–H activations with aryl bromides
Palladium-catalyzed electrophilic C–H fluorination of arenes using oxazoline as a removable directing group
Gutierrez, David A.,Lee, Wan-Chen Cindy,Shen, Yuning,Li, Jie Jack
, p. 5372 - 5376 (2016/11/11)
Dimethyloxazoline was rationally designed to act as a removable ortho-directing group (DG) for the palladium-catalyzed C–H electrophilic fluorination of arenes. Using NFSI as the fluorinating agent, and Pd(II), Ag(I) catalytic system, electrophilic C(sp2–H) ortho-fluorination took place on a variety of aryl substrates to afford the corresponding mono- and di-fluorinated products.
Photoinduced Copper-Catalyzed C-H Arylation at Room Temperature
Yang, Fanzhi,Koeller, Julian,Ackermann, Lutz
supporting information, p. 4759 - 4762 (2016/04/19)
Room-temperature azole C-H arylations were accomplished with inexpensive copper(I) compounds by means of photoinduced catalysis. The expedient copper catalysis set the stage for site-selective C-H arylations of non-aromatic oxazolines under mild reaction conditions, and provides step-economical access to the alkaloid natural products balsoxin and texamine. Copper light: Room-temperature C-H arylations of heteroarenes were accomplished with inexpensive copper compounds by photoinduced catalysis. The expedient copper catalysis leads to site-selective C-H arylations of non-aromatic oxazolines under mild reaction conditions, and provides step-economical access to the alkaloid natural products balsoxin and texamine.
Zincation of 4,4-dimethyloxazoline using TMPZnCl·LiCl. A new preparation of 2-aryloxazolines
Haas, Diana,Hofmayer, Maximilian S.,Bresser, Tomke,Knochel, Paul
supporting information, p. 6415 - 6417 (2015/04/14)
The metalation of 4,4-dimethyloxazoline using TMPZnCl·LiCl provides a stable 2-zincated oxazolinyl reagent which readily undergoes palladium-catalyzed Negishi cross-couplings allowing a new access to 2-aryloxazolines. Cu-mediated acylation and allylation reactions also proceed in good yields. This journal is