41852-28-2Relevant academic research and scientific papers
Isothiourea-Catalyzed Enantioselective Addition of 4-Nitrophenyl Esters to Iminium Ions
Arokianathar, Jude N.,Frost, Aileen B.,Slawin, Alexandra M. Z.,Stead, Darren,Smith, Andrew D.
, p. 1153 - 1160 (2018/02/14)
Isothioureas catalyze the enantioselective addition of 4-nitrophenyl esters to tetrahydroisoquinoline-derived iminium ions. 4-Nitrophenoxide, generated in situ from initial N-acylation of the isothiourea by the 4-nitrophenyl ester, is used to facilitate catalyst turnover in this reaction process. Optimization showed that 4-nitrophenyl esters give the best reactivity in this protocol over a range of alternative aryl esters, with the observed enantioselectivity markedly dependent on the nature of the iminium counterion. Highest yields and enantioselectivity were obtained using iminium bromide ions generated in situ via photoredox catalysis using BrCCl3 and Ru(bpy)3Cl2 (0.5 mol %) and commercially available tetramisole (5 mol %) as the Lewis base catalyst. The scope and limitations of this procedure was developed, giving the desired β-amino amide products in up to 96% yield, 79:21 diastereomeric ratio (dr), and ermajor (2R,1′S) 99.5:0.5.
Synthesis of 2-aryl-3,4-dihydroisoquinolin-2-ium bromides and their in Vitro acaricidal activity against Psoroptes cuniculi
Ma, Yan-Ni,Yang, Xin-Juan,Pan, Le,Hou, Zhe,Geng, Hui-Ling,Song, Xiao-Ping,Zhou, Le,Miao, Fang
, p. 204 - 211 (2013/03/14)
By employing sanguinarine, a natural active quaternary isoquinoline alkaloid, as a model molecule, a series of structurally simple quaternary 2-aryl-3,4-dihydroisoquinolin-2-ium compounds were designed and synthesized and evaluated for in vitro acaricidal activity against P. cuniculi. A new approach towards the title compounds was developed with isochroman as starting material. The results showed that 22 of 24 tested compounds displayed the activity in varying degrees at 0.4 mg/mL. Fourteen compounds were significantly more effective than ivermectin, a standard acaricide, and 6-methoxy dihydrosanguinarine, a derivative of sanguinarine (p0.05). And their comprehensive relative activity was 1.4 to 16.5 times than that of ivermectin and 1.5 to 18.8 times than that of 6-methoxy dihydrosanguinarine. The structure-activity relationship indicated that the introduction of a substituent to N-benzene ring, especially halogen atom and trifluoromethyl group, led to great improvement of the activity. The position of fluorine atom, methyl group and hydroxyl group made very significant effects on the activity. It was concluded that 2-aryl-3,4-dihydroisoquinolin- 2-iums are very promising candidates for the development of new isoquinoline acaricidal agents.
2-(substituted phenyl)-3,4-dihydroisoquinolin-2-iums as novel antifungal lead compounds: Biological evaluation and structure-activity relationships
Hou, Zhe,Yang, Rui,Zhang, Cen,Zhu, Li-Fei,Miao, Fang,Yang, Xin-Juan,Zhou, Le
, p. 10413 - 10424 (2013/10/22)
The title compounds are a class of structurally simple analogues of quaternary benzo[c]phenanthridine alkaloids (QBAs). In order to develop novel QBA-like antifungal drugs, in this study, 24 of the title compounds with various substituents on the N-phenylring were evaluated for bioactivity against seven phytopathogenic fungi using the mycelial growth rate method and their SAR discussed. Almost all the compounds showed definite activities in vitro against each of the test fungi at 50 μg/mL and a broad antifungal spectrum. In most cases, the mono-halogenated compounds 2-12 exhibited excellentactivities superior to the QBAs sanguinarine and chelerythrine. Compound 8 possessed the strongest activities on each of the fungi with EC50 values of 8.88-19.88 μg/mL and a significant concentration-dependent relationship. The SAR is as follows: the N-phenyl group is a high sensitive structural moiety for the activity and the characteristics and position of substituents intensively influence the activity. Generally, electron-withdrawing substituents remarkably enhance the activity while electron-donating substituents cause a decrease of the activity. In most cases, ortha- and para-halogenated isomers were more active than the corresponding m-halogenated isomers. Thus, the title compounds emerged as promising lead compounds for the development of novel biomimetic antifungal agrochemicals. Compounds 8 and 2 should have great potential as new broad spectrum antifungal agents for plant protection.
α-Substituted Phosphonates. 43. Synthesis and Reactivity of 1,2,3,4-Tetrahydroisoquinolin-1-phosphonates
Gross, H.,Ozegowski, S.
, p. 437 - 445 (2007/10/02)
N-Alkyl- and N-arylsubstituted 1,2,3,4-tetrahydroisochinolin-1-phosphonates 1 have been synthesized from the corresponding 3,4-dihydroisochinoliniumbromides 7 and triethylphosphite.The N-unsubstituted 1,2,3,4-tetrahydroisochinolin-1-phosphonate 10 is available starting from the 1,2,3,4-tetrahydroisochinolin-1-phosphonic acid by esterification with triethylformate and splitting off the formyl group of the primarily formed N-formyl derivative 14. - N-Quarternated tetrahydroisochinolines 19 and the 1-phosphorylated derivatives 17, respectively react with triethylphosphite in an unexpected way by dealkylation and not by splitting off the isochinolinring. - By Horner-synthesis with 1 the 1-aralkylidene-isochinolines 23 are available in moderate yields.
