65071-52-5Relevant academic research and scientific papers
Design, Synthesis, and Biological Evaluation of Tetrahydroisoquinoline-Based Histone Deacetylase 8 Selective Inhibitors
Taha, Taha Y.,Aboukhatwa, Shaimaa M.,Knopp, Rachel C.,Ikegaki, Naohiko,Abdelkarim, Hazem,Neerasa, Jayaprakash,Lu, Yunlong,Neelarapu, Raghupathi,Hanigan, Thomas W.,Thatcher, Gregory R. J.,Petukhov, Pavel A.
, p. 824 - 829 (2017/08/16)
Histone deacetylase 8 (HDAC8) is a promising drug target for multiple therapeutic applications. Here, we describe the modeling, design, synthesis, and biological evaluation of a novel series of C1-substituted tetrahydroisoquinoline (TIQ)-based HDAC8 inhibitors. Minimization of entropic loss upon ligand binding and use of the unique HDAC8 "open" conformation of the binding site yielded a successful strategy for improvement of both HDAC8 potency and selectivity. The TIQ-based 3g and 3n exhibited the highest 82 and 55 nM HDAC8 potency and 330- and 135-fold selectivity over HDAC1, respectively. Selectivity over other class I isoforms was comparable or better, whereas inhibition of HDAC6, a class II HDAC isoform, was below 50% at 10 μM. The cytotoxicity of 3g and 3n was evaluated in neuroblastoma cell lines, and 3n displayed concentration-dependent cytotoxicity similar to or better than that of PCI-34051. The selectivity of 3g and 3n was confirmed in SH-SY5Y cells as both did not increase the acetylation of histone H3 and α-tubulin. Discovery of the novel TIQ chemotype paves the way for the development of HDAC8 selective inhibitors for therapeutic applications.
Identification of an Imine Reductase for Asymmetric Reduction of Bulky Dihydroisoquinolines
Li, Hao,Tian, Ping,Xu, Jian-He,Zheng, Gao-Wei
, p. 3151 - 3154 (2017/06/23)
A new imine reductase from Stackebrandtia nassauensis (SnIR) was identified, which displayed over 25- to 1400-fold greater catalytic efficiency for 1-methyl-3,4-dihydroisoquinoline (1-Me DHIQ) compared to other imine reductases reported. Subsequently, an efficient SnIR-catalyzed process was developed by simply optimizing the amount of cosolvent, and up to 15 g L-1 1-Me DHIQ was converted completely without a feeding strategy. Furthermore, the reaction proceeded well for a panel of dihydroisoquinolines, affording the corresponding tetrahydroisoquinolines (mostly in S-configuration) in good yields (up to 81%) and with moderate to excellent enantioselectivities (up to 99% ee).
Method for solvent accelerated selective dehydrogenation of tetrahydroisoquinoline type compound
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Paragraph 0039; 0040; 0041; 0042; 0043, (2017/07/22)
The invention discloses a method for synthesizing 1-substituted-3,4-dihydroisoquinoline through the solvent accelerated selective partial dehydrogenation of a 1-substituted-1,2,3,4-tetrahydroisoquinoline compound. For a simple and easily obtained cyclic amine type compound such as a tetrahydroisoquinoline compound, a corresponding imine compound can be obtained through selective dehydrogenation; the conversion ratio of the cyclic amine type compound is higher; further, the proportion of a partially dehydrogenated product to a fully dehydrogenated product is more than 20 to 1. The method is simple and convenient to operate, is practical, easy and feasible, and is mild in reaction condition; the actual cost is greatly reduced. In addition, a method for synthesizing 3,4-dihydroisoquinoline through the direct dehydrogenation of tetrahydroisoquinoline has the advantages of atom economy and environmental friendliness.
One-Pot N-Deprotection and Catalytic Intramolecular Asymmetric Reductive Amination for the Synthesis of Tetrahydroisoquinolines
Zhou, Huan,Liu, Yuan,Yang, Suhua,Zhou, Le,Chang, Mingxin
, p. 2725 - 2729 (2017/02/26)
A one-pot N-Boc deprotection and catalytic intramolecular reductive amination protocol for the preparation of enantiomerically pure tetrahydroisoquinoline alkaloids is described. The iodine-bridged dimeric iridium complexes displayed superb stereoselectivity to give tetrahydroisoquinolines, including several key pharmaceutical drug intermediates, in excellent yields under mild reaction conditions. Three additives played important roles in this reaction: Titanium(IV) isopropoxide and molecular iodine accelerated the transformation of the intermediate imine to the tetrahydroisoquinoline product; p-toluenesulfonic acid contributed to the stereocontrol.
Palladium carbon catalyzed selective partial dehydrogenation method of tetrahydroisoquinoline
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Paragraph 0044-0047; 0050, (2017/02/09)
The invention relates to a method for synthesis of 1-substituted-3, 4-dihydroisoquinoline by palladium carbon catalyzed selective partial dehydrogenation of a 1-substituted-1, 2, 3, 4-tetrahydroisoquinoline compound. The reaction temperature is 0-80DEG C. For easily available cyclic amine compounds like tetrahydroisoquinoline, a corresponding imine compound can be obtained through selective dehydrogenation, the conversion rate is up to 99%, and the proportion of a partial dehydrogenation product and a complete dehydrogenation product is greater than 20:1. The method provided by the invention has simple and practical operation, the raw materials and catalyst are cheap and easily available, the reaction conditions are mild, and the catalyst can be recycled, thus greatly reducing the actual cost. In addition, the method for synthesis of 3, 4-dihydroisoquinoline through direct dehydrogenation of tetrahydroisoquinoline has the advantages of atom economy and environmental friendliness.
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.
A Titanium(III)-Catalyzed Reductive Umpolung Reaction for the Synthesis of 1,1-Disubstituted Tetrahydroisoquinolines
Luu, Hieu-Trinh,Wiesler, Stefan,Frey, Georg,Streuff, Jan
supporting information, p. 2478 - 2481 (2015/05/27)
A catalytic reductive C1-acylation of 3,4-dihydroisoquinolines is presented that gives direct access to 1,1-disubstituted tetrahydroisoquinolines. The reaction is a titanium(III)-catalyzed reductive umpolung process in which nitriles act as effective acylation agents. The method is highly chemo- and regioselective and is demonstrated in 20 examples. It is well-suited for the large-scale synthesis of functionalized tetrahydroisoquinoline products, which is exemplified in the form of a six-step synthesis of (±)-3-demethoxyerythratidinone. (Figure Presented).
Highly selective partial dehydrogenation of tetrahydroisoquinolines using modified Pd/C
Ji, Yue,Chen, Mu-Wang,Shi, Lei,Zhou, Yong-Gui
, p. 33 - 39 (2015/09/28)
A highly selective procedure has been developed for the partial dehydrogenation of 1-substituted-1,2,3,4-tetrahydroisoquinolines over K3PO4·3H2O-modified Pd/C catalyst. This new method provides facile, atom-economical and environmentally friendly access to 1-substituted-3,4-dihydroisoquinolines without the need for stoichiometric amounts of harmful oxidants. The use of standard Pd/C as a catalyst for this process gave poor chemoselectivity. Pleasingly, the use of a K3PO4·3H2O-modified Pd/C catalyst promoted the partial dehydrogenation of 1-substituted-1,2,3,4-tetrahydroisoquinolines with excellent chemoselectivity by suppressing further dehydroaromatization. Furthermore, conducting the reaction under an atmosphere of oxygen led to further improvements in the chemoselectivity of the dehydrogenation, with the ratio of imine to isoquinoline reaching up to 32/1. The heterogenous Pd/C catalyst could also be recycled and reused at least three times with excellent conversion and chemoselectivity, demonstrating the significantly practical potential of this methodology.
Trimethyl borate/magnesium halide complex-induced one-pot homologation reactions of isoquinoline with dialkyl-TMP-zincate
Seo, Hye Ji,Namgoong, Sung Keon
scheme or table, p. 3594 - 3598 (2012/09/08)
Novel one-pot homologation reactions of isoquinoline with lithium dialkyl-TMP-zincate?2MgBrCl/trimethyl borate are described. 1-Alkylisoquinolines (2, 3A, 4A, 5A, 6, and 7) and 1-alkyl-3,4- dihydroisoquinolines (3B, 4B, and 5B) are easily prepared under t
A highly efficient and enantioselective access to tetrahydroisoquinoline alkaloids: Asymmetric hydrogenation with an iridium catalyst
Chang, Mingxin,Li, Wei,Zhang, Xumu
, p. 10679 - 10681 (2011/12/05)
Efficient and enantioselective: Using the iodine-bridged dimeric iridium complex [{Ir(H)[(S,S)-(f)-binaphane]}2(μ-I)3] +I- (1) a wide range of tetrahydroisoquinoline alkaloids, including the substructure of the pharmaceutical drug solifenacin, were obtained with excellent enantioselectivities and high turnover numbers (see scheme). Copyright
