881-03-8Relevant articles and documents
Novel functionalized indigo derivatives for organic electronics
Klimovich, Irina V.,Zhilenkov, Alexander V.,Кuznetsova, Lidiya I.,Frolova, Lubov A.,Yamilova, Olga R.,Troyanov, Sergey I.,Lyssenko, Konstantin A.,Troshin, Pavel A.
, (2020/11/24)
A series of nine novel indigo derivatives, including diiodoindigo, octahalogenated indigoids and compounds with extended π-conjugated system, were synthesized, characterized and investigated as semiconductor materials in organic field-effect transistors (OFETs). Among them, 6,6′-diiodoindigo demonstrated the ambipolar behavior with balanced p-type and n-type mobilities. The complete substitution of hydrogens at the indigo core with halogen atoms led to low electron mobilities in OFETs. An extension of the conjugated system through the introduction of small aromatic substituents (thiophene and phenyl) resulted in predominant p-type behavior. Fusion of aromatic rings resulted in z-shaped dibenzoindigo, which showed poor charge transport properties due to the non-optimal arrangement of molecules along each other in the crystal lattice. The acquired data fulfilled the previously reported model based on the relationship between the chemical nature of substituents and their positions at the indigo core, optoelectronic properties of materials and their performance in OFETs. The results of this study will be useful for rational design of a new generation of the indigo-based semiconductors for biocompatible organic electronics.
Corey-Chaykovsky Cyclopropanation of Nitronaphthalenes: Access to Benzonorcaradienes and Related Systems
Antoniak, Damian,Barbasiewicz, Micha?
supporting information, p. 9320 - 9325 (2019/11/19)
Nitronaphthalene derivatives react as Michael acceptors in the Corey-Chaykovsky reaction with alkyl phenyl selenones and alkyl diphenyl sulfonium salts. Mechanistic studies reveal that sterically demanding substituents at the carbanionic center favor formation of cyclopropanes and suppress competitive β-elimination to the alkylated products. The transformation, demonstrated also on heterocyclic nitroquinoline and nitroindazolines, is an example of transition metal-free dearomatization method.
Ceric ammonium nitrate (CAN) as oxidizing or nitrating reagent for organic reactions in ionic liquids
Deleersnyder, Karen,Schaltin, Stijn,Fransaer, Jan,Binnemans, Koen,Parac-Vogt, Tatjana N.
scheme or table, p. 4582 - 4586 (2009/10/11)
The reaction of ceric ammonium nitrate, (NH4)2[Ce(NO3)6] or CAN, with naphthalene and 2-methylnaphthalene in the ionic liquid 1-ethyl-3-methylimidazolium triflate showed that the reaction products are strongly d
A facile synthesis of 2-methylquinolines via Pd-catalyzed aza-Wacker oxidative cyclization
Zhang, Zuhui,Tan, Jiajing,Wang, Zhiyong
, p. 173 - 175 (2008/09/18)
(Chemical Equation Presented) A novel Pd-catalyzed Wacker-type oxidative cyclization under air is described. By using this cyclization, a series of 2-methylquinolines are readily prepared with good yields under mild conditions.
Selective ortho methylation of nitroheteroaryls by vicarious nucleophilic substitution
Achmatowicz, Michal,Thiel, Oliver R.,Gorins, Gilles,Goldstein, Corinne,Affouard, Caroline,Jensen, Randy,Larsen, Robert D.
, p. 6793 - 6799 (2008/12/22)
(Chemical Equation Presented) An efficient and scalable three-step one-pot approach to 6-methyl-5-nitroisoquinoline (1) from inexpensive 5-nitroisoquinoline, utilizing the vicarious nucleophilic substitution (VNS) as a key step, is described. The optimized reaction conditions can be applied to a limited number of other aromatic and heteroaromatic nitro compounds. Attempts to understand the observed selectivity in the VNS step led to the discovery of two new reaction pathways under VNS conditions, one leading to an isoxazole and the other resulting in the formal cyclopropanation of an aromatic nitro compound.
Indium triflate as a recyclable catalyst for the nitration of aromatic compounds without a halogenated solvent
Yin, Wan-Po,Shi, Min
, p. 549 - 551 (2007/10/03)
Indium triflate [In(OTf)3] was found to be excellent catalyst (0.5 or 2.0 mol%) for the mononitration of aromatic compounds using a single equivalent of nitric acid (60 or 90%, 1.0 equiv.) without using a halogenated solvent. The side product is water and the indium triflate catalyst can be readily recovered from the aqueous phase and reused.
New Types of Very Efficient Photolabile Protecting Groups Based upon the [2-(2-Nitrophenyl)propoxy]carbonyl (NPPOC) Moiety
Buehler, Sigrid,Lagoja, Irene,Giegrich, Heiner,Stengele, Klaus-Peter,Pfleiderer, Wolfgang
, p. 620 - 659 (2007/10/03)
Based upon the photolabile [2-(2-nitrophenyl)propoxy]carbonyl group (NPPOC), a large number of modified 2-(2-nitrophenyl)propanol derivatives substituted at the phenyl ring (see 23-34 and 57-76) as well as at the side-chain (see 85-92 and 95-98) were synthesized to improve the photoreactivity of this new type of photolabile entity. The phenyl moiety was also exchanged by the naphthalenyl group (see 102, 103, 105, 108, 110, 113, and 114), the thienyl substituent (see 115, 117, 118, and 120), and the benzothienyl substituent (see 121). The 2-(2-nitroaryl- and heteroaryl) propanols were converted with diphosgene into the corresponding carbonochloridates, which reacted subsequently with thymidine to the thymidine 5′-(protected carbonates) 123-178 as the main reaction products. In several cases, the corresponding 3′-carbonates and 3′,5′ -dicarbonates 179-212 were also isolated and characterized. Photolysis studies under standardized conditions (see Table) indicated that the rate of photocleavage varies in a broad range depending on the substituents. So far, the thymidine 5′-[2-(5-halo-2-nitrophenyl)propyl carbonates] 127-129, 5′-[2-(nitro[1,1′-biphenyl]3-yl)propyl carbonates] 136-139, 5′-{2-[2-nitro-5-(thianthren-1-yl)phenyl]propyl carbonate} (140), 5′-[2-(5-naphthalenyl-2-nitrophenyl)propyl carbonates] 141 and 142, and 5′-[2-(2-nitro-5-thienylphenyl)propyl carbonates] 143 and 144 showed the best properties regarding fast and uniform deprotection. Since the nucleobases of 213-215 do not influence the photocleavage features, in general, the new type of photolabile building blocks allows in form of their 3′ -phosphoramidites the photolithographic formation of high-quality biochips.
Selective nitration of aromatic compounds with bismuth subnitrate and thionyl chloride
Muathen, Hussni A.
, p. 593 - 598 (2007/10/03)
Bismuth subnitrate/thionyl chloride have been found to be an efficient combination of reagents for nitration of a wide range of aromatic compounds in dichloromethane. Phenols, in particular, were easily mononitrated and dinitrated with the reagents by controlling the stoichiometry.
First use of axially chiral thioamides for the stereocontrol of C-C bond formation
Dantale, Shubhada,Reboul, Vincent,Metzner, Patrick,Philouze, Christian
, p. 632 - 640 (2007/10/03)
Several N-aryl-substituted thioamides with an axis of chirality along the N-C(aryl) bond were prepared in good to excellent yields. NMR spectra revealed preferences for the E rotamer (along the N-C(=S) bond). X-ray crystallographic analysis showed that the planes of the aryl and thioamide groups were almost perpendicular (79°). For the first time, these atropisomeric thioamides were used for an asymmetric Claisen rearrangement. LDA deprotonation led selectively to the enethiolates of Z stereochemistry, and subsequent reaction with a variety of allyl halides furnished S-allyl keteneaminothioacetals. These intermediates were not detected as they rearranged readily to γ-unsaturated thioamides in good to high yields and diastereoselectivities up to 88:12. Chemical correlation allowed the assignment of the (aR*,2R*) configuration to the major diastereoisomer. A model was proposed to explain the stereochemical course of the thio-Claisen rearrangement.
Synthesis of 2,1-benzisoxazole derivatives from nitroarenes and CH acids in aprotic media
Wrobel
, p. 2384 - 2388 (2007/10/03)
DBU/MgCl2 mediated reaction between nitroarenes and some CH acids bearing leaving group lead to 2,1-benzisoxazole derivatives under aprotic conditions. Ortho-directing effect was observed.
