90584-93-3Relevant academic research and scientific papers
p-TSA-Based DESs as “Active Green Solvents” for Microwave Enhanced Cyclization of 2-Alkynyl-(hetero)-arylcarboxylates: an Alternative Access to 6-Substituted 3,4-Fused 2-Pyranones
Curti, Fabiola,Tiecco, Matteo,Pirovano, Valentina,Germani, Raimondo,Caselli, Alessandro,Rossi, Elisabetta,Abbiati, Giorgio
, p. 1904 - 1914 (2019/02/26)
In this paper, we describe the use of p-TSA based Deep Eutectic Solvents (DESs) as alternative environmental-friendly “active” solvents for the microwave-mediated synthesis of 6-substituted 3,4-fused 2-pyranones, and in particular isocoumarins, starting from 2-alkynyl-(hetero)arylcarboxylates. When the alkyne terminus bears a neutral or an electron-donating group (EDG), the reactions are fast, clean and highly regioselective, to give the 6-endo-dig cyclization products in good to excellent yields. For substrates bearing an electron-withdrawing group (EWG) on the alkyne end, the regioselectivity can be tuned by adding a small amount of silver(I) triflate as co-catalyst. DES was demonstrated to be reusable without loss of efficiency in terms of reaction yields. Based on experimental evidence and previous findings, two competitive mechanisms working simultaneously are proposed to explain the outcomes and the regioselectivity issues.
Silver triflate/: P -TSA co-catalysed synthesis of 3-substituted isocoumarins from 2-alkynylbenzoates
Gianni, Jonathan,Pirovano, Valentina,Abbiati, Giorgio
, p. 3213 - 3219 (2018/05/17)
In this paper, we describe the silver triflate/p-toluenesulfonic acid co-catalysed synthesis of seventeen isocoumarins and two thieno[2,3-c]pyran-7-ones starting from 2-alkynylbenzoates and 3-alkynylthiophene-2-carboxylates, respectively. The reaction proceeds with absolute regioselectivity under mild reaction conditions and low catalyst loading, to afford the desired products in good to excellent yields. A conceivable reaction mechanism is proposed and supported by isotope-exchange tests, 1H NMR studies and ad hoc experiments.
ISOCHROMENE DERIVATIVES AS PHOSPHOINOSITIDE 3-KINASES INHIBITORS
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Page/Page column 111, (2015/07/07)
The invention relates to compounds inhibiting phosphoinositide 3-kinases (PI3K), to pharmaceutical compositions comprising them and therapeutic use thereofin the treatment of disorders associated with PI3K enzymes.
ISOCHROMENE DERIVATIVES AS PHOSHOINOSITIDE 3-KINASES INHIBITORS
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Paragraph 0786; 0787, (2015/06/24)
Compounds of formula (I) described herein are useful for inhibiting phosphoinositide 3-kinases (PI3K) and the treatment of disorders associated with PI3K enzymes.
Synthesis of isocoumarins: Rhenium complex-catalyzed cyclization of 2-ethynylbenzoic acids
Umeda, Rui,Yoshikawa, Shunya,Yamashita, Kouji,Nishiyama, Yutaka
, p. 2172 - 2179 (2015/12/12)
When 2-ethynylbenzoic acids were treated with a catalytic amount of a rhenium complex, such as ReCl(CO)5, 6-endo cyclization of 2-ethynylbenzoic acids proceeded with a high selectivity to give the corresponding isocoumarins in moderate to good yields.
Iodine-mediated neighboring group assisted synthesis of unsymmetrical 1,2-diketone/benzil derivatives from o-(alkynyl)benzamides
Majumdar,Ansary, Inul,De, Rajendra Narayan,Roy
experimental part, p. 2951 - 2958 (2011/10/19)
A facile synthesis of 1,2-diketone derivatives have been achieved from o-(alk-1-ynyl)benzamide derivatives in good to excellent yields by molecular iodine-catalyzed electrophilic reaction. The reaction proceeds via formation of an (isochromenylidene)benze
Cycloisomerization of γ- and δ-acetylenic acids catalyzed by gold(I) chloride
Marchal, Estelle,Uriac, Philippe,Legouin, Béatrice,Toupet, Lo?c,Weghe, Pierre van de
, p. 9979 - 9990 (2008/02/13)
We have developed a gold(I)-catalyzed intramolecular cyclization of γ- and δ-alkyne acids in mild conditions yielding various alkylidene lactones. Whereas a slight electronic effect of the R group was observed on the regioselectivity, bulky substituents o
Regioselective synthesis of natural and unnatural (Z)-3-(1- alkylidene)phthalides and 3-substituted isocoumarins starting from methyl 2- hydroxybenzoates
Bellina, Fabio,Ciucci, Donatella,Vergamini, Piergiorgio,Rossi, Renzo
, p. 2533 - 2545 (2007/10/03)
(Z)-3-(1-Alkylidene)phthalides and 3-substituted isocoumarins, which include compounds bearing a substituent on their benzene ring, have been selectively and efficiently synthesized by a new protocol which involves: (i) the conversion of methyl 2-hydroxybenzoates into the corresponding nonaflates; (ii) Pd-catalyzed alkynylation reactions of these derivatives; (iii) the conversion of the so obtained methyl 2-(1-alkynyl)benzoates into the corresponding carboxylic acids followed by a transition metal-catalyzed heteroannulation reaction. This procedure has been used to prepare either natural products such as senkyunolide B, senkyunolide C, 3-propylisocoumarin and artemidin, or the MEM-ether of senkyunolide E. The regioselectivity of the transition metal-catalyzed cyclization reactions of 2-(1-alkynyl)benzoic acids has proven to be affected either by the catalyst used or the type of 1- alkynyl group present in these carboxylic acids. (C) 2000 Elsevier Science Ltd.
Synthesis of 6H-indolo[2,3-b][1,6]naphthyridines and related compounds as the 5-aza analogues of ellipticine alkaloids
Zhang,Shi,Zhang,Wang
, p. 7977 - 7983 (2007/10/03)
Treatment of 2-(1-alkynyl)phenyl isocyanates 6 with the iminophosphorane 14 produced in situ the benzoenynyl carbodiimides 15. Thermolysis of 15 under refluxing p-xylene furnished the 6H-indolo[2,3-b][1,6]naphthyridines 5, which could be regarded as the 5-aza analogues of ellipticine alkaloids. Similarly, condensation of 6 with the iminophosphorane 20 led to the formation of the 6H-indolo[2,3-b][1,5]naphthyridines 25 as the major isomer and the 10H-indolo[2,3-b][1,7]naphthyridines 26 as the minor isomer. The indolonaphthyridines 32, 33, and 34 having a methoxyl substituent were likewise synthesized. Treatment of the diisocyanate 43 with 2 equiv of the iminophosphorane 7 furnished 45 having two indoloquinoline units incorporated in a seven-fused-ring system.
Biradicals from thermolysis of N-[2-(1-alkynyl)phenyl]-N'- phenylcarbodiimides and their subsequent transformations to 6H-indolo[2,3- b]quinolines
Shi, Chongsheng,Zhang, Quan,Wang, Kung K.
, p. 925 - 932 (2007/10/03)
Thermolysis of the carbodiimide 9a in γ-terpinene at 138 °C produced 2-(phenylamino)quinoline (11a, 49%) and the parent 6H-indolo[2,3-b]quinoline (14a, 16%). Apparently, 11a was produced via the biradical 10a followed by hydrogen-atom abstraction from γ-terpinene. A two-step biradical pathway through 12a or a one-step intramolecular Diels-Alder reaction could furnish 13a, which then underwent tautomerization to give 14a. With the carbodiimide 9b having a trimethylsilyl substituent at the acetylenic terminus, thermolysis in refluxing p-xylene at 138 °C produced the 6H-indolo[2,3- b]quinoline 14b (86%) exclusively. Treatment of 14b with 6 N NaOH in refluxing ethanol then furnished 14a in 92% yield. Similarly, the 6H- indolo[2,3-b]quinolines 14c-f were obtained from thermolysis of the carbodiimides 9c-f. The use of the aza-Wittig reaction between 4- methoxyphenyl isocyanate and the iminophosphoranes 2d and 2f to produce the corresponding carbodiimides followed by thermolysis furnished the 6H- indolo[2,3-b]quinolines 16d and 16f having a methoxy substituent at the C-2 position. Thermolysis of the carbodiimides 25a and 25b produced 26a and 26b having two indoloquinoline units connected at the 11 and 11' positions with either a three-carbon or a five-carbon tether. Using 1,4-phenylene diisocyanate for the aza-Wittig reaction with 2 equiv of the iminophosphorane 2g followed by thermolysis furnished 31 (66%) having two indoloquinoline units incorporated in the seven fused rings.
