135684-75-2

Upstream product

• 874-60-2 4-methyl-benzoyl chloride 
• 38925-77-8 4-methyl-N-(2-phenylethyl)benzamide 
• 64-04-0 phenethylamine 
• 1196-38-9 3,4-dihydroisoquinolin-1(2H)-one 
• 61305-03-1 1-(4'-methylphenyl)-3,4-dihydroisoquinoline 

Relevant academic research and scientific papers

Asymmetric Transfer Hydrogenation of Unhindered and Non-Electron-Rich 1-Aryl Dihydroisoquinolines with High Enantioselectivity

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

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.

A method catalyzed by iridium and used for bidirectional enantioselective synthesis of chiral tetrahydroisoquinoline

A method catalyzed by iridium and used for bidirectional enantioselective synthesis of chiral tetrahydroisoquinoline is provided. A catalysis system adopted by the method is a chiral diphosphine complex of iridium. By utilizing a single chiral source and

A one-pot process for the enantioselective synthesis of tetrahydroquinolines and tetrahydroisoquinolines: Via asymmetric reductive amination (ARA)

Asymmetric reductive amination for the synthesis of both chiral tetrahydroquinolines (THQs) and tetrahydroisoquinolines (THIQs) has been realized with an Ir/ZhaoPhos catalytic system via a one-pot N-Boc deprotection/intramolecular asymmetric reductive amination (ARA) sequence. Control experiments reveal that HCl plays a vital role to the success of this transformation. The HCl acid assists the removal of the N-Boc protecting group and also provides chloride ions to interact with the thiourea moiety in ZhaoPhos, thus leading to excellent reaction enantiocontrol.

Dual Stereocontrol for Enantioselective Hydrogenation of Dihydroisoquinolines Induced by Tuning the Amount of N-Bromosuccinimide

An efficient dual stereocontrol in iridium-catalyzed hydrogenation of 1-substituted 3,4-dihydroisoquinolines was realized by tuning the amount of N-bromosuccinimide using chiral ligand of single configuration, providing both enantiomers of 1-substituted 1,2,3,4-tetrahydroisoquinolines with up to 89% ee (S) and 98% ee (R), respectively. Dual activation role of N-bromosuccinimide is proposed to be responsible for the reversal of enantioselectivity under two hydrogenation conditions.

Enantioselective synthesis of 1-Aryl-substituted tetrahydroisoquinolines employing imine reductase

Tetrahydroisoquinolines (THIQs) with a C1-aryl-substituted groups are common in many natural and synthetic compounds of biological importance. Currently, their enantioselective synthesis are primarily reliant on chemical catalysis. Enzymatic synthesis using imine reductase is very attractive, because of the cost-effectiveness, high catalytic efficiency, and enantioselectivity. However, the steric hindrance of the 1-aryl substituents make this conversion very challenging, and current successful examples are mostly restricted to the simple alkyl-THIQs. In this report, through extensive evaluation of a large collection of IREDs (including 88 enzymes), we successfully identified a panel of steric-hindrance tolerated IREDs. These enzymes are able to convert meta- and para-substituted chloro-, methyl-, and methoxyl-benzyl dihydroisoquinolines (DHIQs) into corresponding R- or S- THIQs with very high enantioselectivity and conversion. Among them, the two most hindrance-tolerated enzymes (with different stereospecificity) are also able to convert ortho-substituted chloro-, methyl-, and methoxyl-benzyl DHIQs and dimethoxyl 1-chlorobenzyl-DHIQs with good enantiometric excess. Furthermore, using in silico modeling, a highly conserved tryptophan residue (W191) was identified to be critical for substrate accommodation in the binding cavity of the S-selective IRED (IR45). Replacing W191 with alanine can dramatically increase the catalytic performance by decreasing the Km value by 2 orders of magnitude. Our results provide an effective route to synthesize these important classes of THIQs. Moreover, the disclosed sequences and substrate binding model set a solid basis to generate more-efficient and broad-selective enzymes via protein engineering.

Enantioselective Synthesis of 1-Aryl-Substituted Tetrahydroisoquinolines Through Ru-Catalyzed Asymmetric Transfer Hydrogenation

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.

Asymmetric transfer hydrogenation of 1-phenyl dihydroisoquinolines using Ru(II) diamine catalysts

A new [Ru(II)(η6-p-cymene)(1R,2R)-N-((1S,2S)-borneol-10- sulfonyl)-1,2-diphenylethylenediamine] catalyst for the asymmetric transfer hydrogenation of both 1-alkyl and 1-aryl dihydroisoquinolines has been isolated. For the first time in this type of reaction, the catalyst employs an N-alkylsulfonyl group instead of N-arylsulfonyl.