15547-57-6Relevant academic research and scientific papers
Asymmetric Transfer Hydrogenation of Unhindered and Non-Electron-Rich 1-Aryl Dihydroisoquinolines with High Enantioselectivity
Barrios-Rivera, Jonathan,Xu, Yingjian,Wills, Martin
supporting information, p. 6283 - 6287 (2020/09/02)
The use of arene/Ru/TsDPEN catalysts bearing a heterocyclic group on the TsDPEN in the asymmetric transfer hydrogenation (ATH) of dihydroisoquinolines (DHIQs) containing meta- or para-substituted aromatic groups at the 1-position results in the formation of products of high enantiomeric excess. Previously, only 1-(ortho-substituted)aryl DHIQs, or with an electron-rich fused ring gave products with high enantioselectivity; therefore, this approach solves a long-standing challenge for imine ATH.
Josiphos-Type Binaphane Ligands for Iridium-Catalyzed Enantioselective Hydrogenation of 1-Aryl-Substituted Dihydroisoquinolines
Nie, Huifang,Zhu, Yupu,Hu, Xiaomu,Wei, Zhao,Yao, Lin,Zhou, Gang,Wang, Pingan,Jiang, Ru,Zhang, Shengyong
, p. 8641 - 8645 (2019/10/17)
Convenient synthesis and useful application of a series of Josiphos-type binaphane ligands were described. The iridium complexes of these chiral diphosphines displayed excellent enantioselectivity and good reactivity in the asymmetric hydrogenation of challenging 1-aryl-substituted dihydroisoquinoline substrates (full conversions, up to >99% ee, 4000 TON). The use of 40% HBr (aqueous solution) as an additive dramatically improved the asymmetric induction of these catalysts. This transformation provided a highly efficient and enantioselective access to chiral 1-aryl-substituted tetrahydroisoquinolines, which were of great importance and common in natural products and biologically active molecules.
Solvent-promoted highly selective dehydrogenation of tetrahydroisoquinolines without catalyst and hydrogen acceptor
Feng, Guang-Shou,Ji, Yue,Liu, Hui-Fang,Shi, Lei,Zhou, Yong-Gui
supporting information, p. 747 - 749 (2016/02/05)
An unusual solvent DMF-promoted dehydrogenation of 1-substituted 1,2,3,4-tetrahydroisoquinolines to synthesize cyclic imines is described. This environmentally friendly reaction features no requirement of any metal catalysts, oxidants, or hydrogen acceptors. A wide range of structurally varied 3,4-dihydroisoquinolines can be obtained with good yields and excellent chemoselectivities.
Total synthesis of racemic 1-aryl-tetrahydroisoquinoline alkaloids
ábrányi-Balogh, Péter,F?ldesi, Tamás,Milen, Mátyás
, p. 1907 - 1912 (2015/10/29)
A new synthetic route was developed for the preparation of natural products cryptostyline I, II, III and 1-phenyl-6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline. The Liebeskind-Srogl palladium-catalyzed carbon-carbon cross-coupling protocol was use
Enantioselective Synthesis of 1-Aryl-Substituted Tetrahydroisoquinolines Through Ru-Catalyzed Asymmetric Transfer Hydrogenation
Perez, Marc,Wu, Zi,Scalone, Michelangelo,Ayad, Tahar,Ratovelomanana-Vidal, Virginie
, p. 6503 - 6514 (2015/10/19)
A convenient and general asymmetric transfer hydrogenation of a wide array of 1-aryl-3,4-dihydroisoquinoline derivatives using a [RuIICl(η6-benzene)TsDPEN] complex in combination with a 5:2 HCOOH-Et3N azeotropic mixture as a hydrogen source was developed. Under mild reaction conditions, the described catalytic transformation secured a practical synthetic access to the corresponding valuable chiral 1-aryltetrahydroisoquinoline units with high atom economy, a broad substrate scope, high isolated yields (up to 97%) and good to excellent enantioselectivities (up to 99% ee). It was found that the stereochemical outcome of the reaction was strongly influenced by both the structure of the catalyst and the substituents present on the substrate. The synthetic utility of the present protocol has been demonstrated through the asymmetric synthesis of several biologically important alkaloids including the antiepileptic drug agent 1c, as well as (-)-nor-cryptostyline alkaloids I and II.
Efficient and Practical Syntheses of Enantiomerically Pure (S)-(-)-Norcryptostyline I, (S)-(-)-Norcryptostyline II, (R)-(+)-Salsolidine and (S)-(-)-Norlaudanosine via a Resolution-Racemization Method
Zhu, Ruiheng,Xu, Zhangli,Ding, Wei,Liu, Shiling,Shi, Xiaoxin,Lu, Xia
, p. 1039 - 1048 (2016/02/18)
Four racemic tetrahydroisoquinolines (RS)-(±)-1-4 were prepared from homoveratrylamine via amidation, Bischler-Napieralski reaction and the subsequent reduction. The enantiomerically pure tetrahydroisoquinolines (S)- (-)-norcryptostyline I [(S)-(-)-1], (S)-(-)-norcryptostyline II [(S)-(-)-2], (R)-(+)-salsolidine [(R)-(+)-3] and (S)-(-)-norlaudanosine [(S)-(-)-4] were then obtained in 45%, 40%, 41% and 38% yields, respectively, via resolution of the racemic compounds (RS)-(±)-1-4 with half equivalent of chiral acids. In addition, the enantiomerically enriched compounds (R)-(+)-1, (R)-(+)-2, (S)-(-)-3 and (R)-(+)-4 from the mother liquors were efficiently racemized via a one-pot redox method in almost quantitative yields.
Restraining the flexibility of the central linker in terameprocol results in constrained analogs with improved growth inhibitory activity
Ho, Sherman Si Han,Go, Mei Lin
, p. 6127 - 6133 (2013/11/06)
The semi-synthetic lignan terameprocol inhibits the transcription of several inflammatory and oncogenic genes and has been evaluated for its anti-cancer properties. Here we investigated the effect of restricting the flexibility of the carbon linker connecting the terminal rings of terameprocol on its growth inhibitory activity. Conformational restriction was explored by introducing unsaturation, inserting polar entities with limited flexibility and cyclization of the connecting linker. Twenty three compounds were synthesized and evaluated on a panel of malignant human cells. The most promising compounds were those with non-polar linkers, as seen in butadiene 1a and the cyclized benzylideneindane analog 7. Both compounds were more potent than terameprocol on pancreatic BxPC-3 cells with GI50 values of 3.4 and 8.1 μM, respectively. Selected isomers of 1a (E,E) and 7 (Z) adopted low energy bent conformations that mimicked the low energy conformer of terameprocol. It is tempting to propose that conformational similarity to terameprocol may have contributed to their good activity. The scaffolds of 1a and 7 should be further investigated for their anticancer potential.
Palladium-catalyzed intramolecular C-H amidation: Synthesis and biological activities of indolobenzazocin-8-ones
Boonya-Udtayan, Sasiwadee,Ruchirawat, Somsak,Mahidol, Chulabhorn,Thasana, Nopporn,Eno, Meredith
, p. 10293 - 10301,9 (2012/12/12)
The synthesis of multi ring-fused indolobenzazocinone derivatives, an antimitotic agent, has been carried out using palladium-catalyzed C-H activation/intramolecular amidation of benzo[d]azocinones, which were synthesized by the ring annulations of dihydroisoquinolines and azlactone in refluxing acetonitrile. The target compounds, indolobenzazocin-8-one derivatives, were evaluated for their cytotoxicity against the cancer cell lines HUCCA-1, A549, HepG2, and MOLT-3. The results showed that an unsubstituted indolobenzazocin-8-one 1e exhibited very good activities in the nanomolar IC50 value range (HepG2 and MOLT-3).
Palladium-catalyzed intramolecular C-H amidation: Synthesis and biological activities of indolobenzazocin-8-ones
Boonya-Udtayan, Sasiwadee,Eno, Meredith,Ruchirawat, Somsak,Mahidol, Chulabhorn,Thasana, Nopporn
, p. 10293 - 10301 (2013/01/15)
The synthesis of multi ring-fused indolobenzazocinone derivatives, an antimitotic agent, has been carried out using palladium-catalyzed C-H activation/intramolecular amidation of benzo[d]azocinones, which were synthesized by the ring annulations of dihydroisoquinolines and azlactone in refluxing acetonitrile. The target compounds, indolobenzazocin-8-one derivatives, were evaluated for their cytotoxicity against the cancer cell lines HUCCA-1, A549, HepG2, and MOLT-3. The results showed that an unsubstituted indolobenzazocin-8-one 1e exhibited very good activities in the nanomolar IC50 value range (HepG2 and MOLT-3).
Mild and efficient syntheses of 1-aryl-3,4-dihydroisoquinolines and 1-aryl-3,4-dihydro-β-carbolines via regiospecific β-eliminations of the corresponding N-tosyl-1,2,3,4-tetrahydroisoquinolines and N-tosyl-1,2,3,4-tetrahydro-β-carbolines
Dong, Jing,Shi, Xiao-Xin,Xing, Jing,Yan, Jing-Jing
experimental part, p. 2806 - 2817 (2012/07/16)
(Chemical Equation Presented) Treatment of N-tosyl-1-aryl-1,2,3,4- tetrahydro-isoquinolines or N-tosyl-1-aryl-1, 2,3,4-tetrahydro-β-carbolines with a strong base such as NaOH or KOH at 70 °C in dimethylsulfoxide (DMSO) produced 1-aryl-3,4-dihydroisoquinolines or 1-aryl-3,4-dihydro-β- carbolines in good yields via mild and regiospecific β-eliminations. A dramatic solvent effect was observed, DMSO was crucial for the reactions. The temperature is also crucial for the reactions and should be kept between 60 and 80 °C. Copyright Taylor & Francis Group, LLC.
