5079-91-4Relevant academic research and scientific papers
Cyclic analogue of S-benzylisothiourea that suppresses kynurenine production without inhibiting indoleamine 2,3-dioxygenase activity
Fukuda, Miwa,Sasaki, Tomomi,Hashimoto, Tomoko,Miyachi, Hiroyuki,Waki, Minoru,Asai, Akira,Takikawa, Osamu,Ohno, Osamu,Matsuno, Kenji
, p. 2846 - 2849 (2018/07/30)
Kynurenine is biosynthesised from tryptophan catalysed by indoleamine 2,3-dioxygenase (IDO). The abrogation of kynurenine production is considered a promising therapeutic target for immunological cancer treatment. In the course of our IDO inhibitor programme, formal cyclisation of the isothiourea moiety of the IDO inhibitor 1 afforded the 5-Cl-benzimidazole derivative 2b-6, which inhibited both recombinant human IDO (rhIDO) activity and cellular kynurenine production. Further derivatisation of 2b-6 provided the potent inhibitor of cellular kynurenine production 2i (IC50 = 0.34 μM), which unexpectedly exerted little effect on the enzymatic activity of rhIDO. Elucidation of the mechanism of action revealed that compound 2i suppresses IDO expression at the protein level by inhibiting STAT1 expression in IFN-γ-treated A431 cells. The kynurenine-production inhibitor 2i is expected to be a promising starting point for a novel approach to immunological cancer treatment.
Enantiospecific Synthesis of ortho-Substituted Benzylic Boronic Esters by a 1,2-Metalate Rearrangement/1,3-Borotropic Shift Sequence
Aichhorn, Stefan,Bigler, Raphael,Myers, Eddie L.,Aggarwal, Varinder K.
, p. 9519 - 9522 (2017/07/25)
Coupling reactions between benzylamines and boronic esters have been investigated. ortho-Lithiated benzylamines react with boronic esters and a N-activator to afford ortho-substituted benzylic boronic esters with formal 1,1′-benzylidene insertion into the C-B bond. The reaction occurs by a SN2′ elimination and 1,2-metalate rearrangement of the N-activated boronate complex to afford a dearomatized intermediate, which undergoes a Lewis-acid catalyzed 1,3-borotropic shift to afford the boronic ester products in high yield and with excellent enantiospecificity. The use of enantioenriched α-substituted benzylamines gave the corresponding secondary boronic esters with high ee.
Transition-metal-free semihydrogenation of diarylalkynes: Highly stereoselective synthesis of trans -alkenes using Na2S·9H 2O
Chen, Zhengwang,Luo, Miaoting,Wen, Yuelu,Luo, Guotian,Liu, Liangxian
supporting information, p. 3020 - 3023 (2014/06/23)
A highly stereoselective and efficient transition-metal-free semihydrogenation of internal alkynes to E-alkenes using cheap and green water as hydrogen donor is described. The reactions are conducted under convenient conditions and provide products in good to excellent yields, with broad substrate scope, including a variety of diarylalkynes.
Synthesis of substituted 2-arylindanes from e -(2-stilbenyl)methanols via lewis acid-mediated cyclization and nucleophililc transfer from trialkylsilyl reagents
Sarnpitak, Pakornwit,Trongchit, Kanokrat,Kostenko, Yulia,Sathalalai, Supaporn,Gleeson, M. Paul,Ruchirawat, Somsak,Ploypradith, Poonsakdi
, p. 8281 - 8296 (2013/09/24)
A preparative method for the synthesis of functionalized 2-arylindanes has been developed via the Lewis acid-mediated ring closure of stilbenyl methanols followed by nucleophilic transfer from trialkylsilyl reagents. The reactions gave the corresponding p
Novel cyclization cascades to functionalized indanes and tetrahydronaphthalenes
Khan, Zulfiqar A.,Iwaoka, Michio,Wirth, Thomas
experimental part, p. 6639 - 6646 (2010/10/19)
Cyclization cascades involving C-C bond formations followed by lactonization reactions provide fast access to structurally complex tricyclic indane and tetrahydronaphthalene derivatives. Crown Copyright
A one-pot synthesis of (E)-disubstituted alkenes by a bimetallic [Rh-Pd]-catalyzed hydrosilylation/hiyama cross-coupling sequence
Thiot, Carine,Schmutz, Marc,Wagner, Alain,Mioskowski, Charles
, p. 8971 - 8978 (2008/09/17)
A bimetallic [Rh-Pd] catalyst was prepared by soaking into an iodide ionic gel an equimolar solution of [RhCl(PPh3)3] and Pd(OAc)2 in CH2Cl2. Its catalytic activity was evaluated by rhodium-catalyzed hydrosilylation (H), palladium-catalyzed Hiyama coupling (C), and in the one-pot hydrosilylation/Hiyama coupling sequence (H/C). It was found that the homogeneous combination [RhCl(PPh3) 3]/NaI was a superior system compared to the polyionic mono- and bimetallic rhodium catalysts in the hydrosilylation of terminal alkynes. Interestingly, the most effective catalyst in terms of stereo- and chemoselectivities was observed to be the bimetallic ionic gel [Rh-Pd] in the one-pot process leading to (E)-alkenes with good yields. The remarkable stereocontrol is ascribed to a beneficial Pd-catalyzed isomerization from the mixture of stereoisomeric vinylsilanes obtained in the initial hydrosilylation step into the more stable (E)-adduct. The [Rh-Pd] heterogeneous catalyst also showed a higher chemoselectivity than the homogeneous catalytic combination, and no detrimental formation of Sonogashira side product was observed due to an ionic-gel-mediated kinetic modulation. To illustrate its scope and limitations, the described one-pot bimetallic catalytic sequence was extended to functionalized terminal alkynes and various iodide substrates. Conjugated systems, such as hydroxycinnamaldehyde, dienes, and trienes, were synthesized in good overall yields. To avoid deactivation of the Rh species, N-heterocyclic iodides had to be added sequentially after completion of hydrosilylation.
Reactivity of functionalized arylcarbenes. 2-Phenylethyl side chains and hetero analogues
Kirmse, Wolfgang,Konrad, Wolfgang,Oezkir, Ismail S.
, p. 9935 - 9964 (2007/10/03)
Phenylcarbenes with -X-CH2Ph and -CH2-X-Ph (X = CH2, O, SiMe2) groups in the ortho position were generated thermally and photolytically from diazo or tosylhydrazone precursors. Stereorandom insertion reactions with β-C-H bonds were observed, pointing to a triplet abstraction-recombination mechanism. Large kinetic and stereochemical deuterium isotope effects support this notion. The ample formation of benzocyclobutenes from 2-CH2-X-Ph substrates is due to insertion of the carbenes into ArCH2-X bonds. Addition to the terminal phenyl groups competes with C-H and C-X insertion. The results of benzophenone sensitization and of trapping with methanol suggest that the intramolecular reactions of functionalized arylcarbenes proceed, at best, competitively with spin inversion.
Vinyl Azides in Heterocyclic Synthesis. Part 2. Selectivity in the Decomposition of Azidocinnamates with Olefinic ortho-Substituents
Hickey, Deirdre M. B.,Moody, Christopher J.,Rees, Charles W.
, p. 1113 - 1118 (2007/10/02)
Thermolysis of azidocinnamates with an olefinic o-substituent gives products (isoquinolines, azepines, aziridines) formed by selective interaction of the azide, and the derived nitrene, with the olefinic substituent, cyclisation onto the unsubstituted aro
