138350-92-2Relevant articles and documents
Mechanistic studies on the catalytic asymmetric mannich-type reaction with dihydroisoquinolines and development of oxidative mannich-type reactions starting from tetrahydroisoquinolines
Dubs, Christian,Hamashima, Yoshitaka,Sasamoto, Naoki,Seidel, Thomas M.,Suzuki, Shoko,Hashizume, Daisuke,Sodeoka, Mikiko
, p. 5859 - 5871 (2008)
(Chemical Equation Presented) Detailed mechanistic studies on our recently reported asymmetric addition reactions of malonates to dihydroisoquinolines (DHIQs) catalyzed by chiral Pd(II) complexes were carried out. It was found that an N,O-acetal was gener
Direct Phosphonylation of N-Carbamate-tetrahydroisoquinoline by Convergent Paired Electrolysis
Leónel, Eric,Martens, Thierry,Ollivier, Anthony,Rey, Marine,Sengmany, Stéphane
, p. 1191 - 1196 (2020)
Mild experimental conditions for a direct phosphonylation of an easily cleavable N-carbamate-tetrahydroisoquinoline have been described under constant current electrolysis. The developed electrochemical process allowed to prepare α-aminophosphonates in moderate to good yields. On the basis of the experimental results, a mechanism proceeding through a convergent paired electrochemical process was enabled to be postulated.
Lithioarene Cycliacylation and Pd-Catalyzed Aminoethylation/Cyclization to Access Electronically Diverse Saturated Isoquinoline Derivatives
Altenbach, Robert J.,Buchman, Marek,Farney, Elliot P.,Gfesser, Gregory A.,Greszler, Stephen N.,Voight, Eric A.
, p. 776 - 789 (2022/01/14)
We report operationally facile methods for the synthesis of substituted dihydroisoquinolinones and tetrahydroisoquinolines from readily accessible o-bromobenzyl bromides and o-bromobenzaldehydes, respectively. While classical electrophilic aromatic substitution reactions are tailored to the construction of saturated isoquinolines derived from electron-rich precursors, we demonstrate efficient syntheses from electronically diverse substrates to produce cyclized products as single regioisomers.
Synthesis of Amide Enol Carbamates and Carbonates through Cu(OTf)2-Catalyzed Reactions of Ynamides with t-Butyl Carbamates/Carbonates
Han, Pan,Mao, Zhuo-Ya,Li, Ming,Si, Chang-Mei,Wei, Bang-Guo,Lin, Guo-Qiang
, p. 4740 - 4752 (2020/04/30)
A highly regioselective approach to access amide enol carbamates and carbonates 5a-5c′, 7a-7h, and 9 was developed through Cu(OTf)2-catalyzed reactions of ynamides 4 with t-butyl carbamates 2 and 8 and t-butyl carbonates 6. Moreover, this strategy was successfully applied to generate amide enol carbamates 11a-11s and 14a-14f from imides 10 and 13 with ynamides through an N-Boc cleavage-addition ring-opening process. A range of substituents was amenable to this transformation, and the desired amide enol carbamates and carbonates were obtained in moderate to good yields.
Aerobic α-Oxidation of N-Substituted Tetrahydroisoquinolines to Dihydroisoquinolones via Organo-photocatalysis
Aganda, Kim Christopher C.,Hong, Boseok,Lee, Anna
supporting information, p. 1124 - 1129 (2019/01/25)
An efficient visible-light-induced α-oxidation of N-substituted tetrahydroisoquinolines to dihydroisoquinolones has been developed using eosin Y as an organo-photocatalyst and oxygen as a green oxidant. The reactions were carried out under mild reaction conditions; the desired dihydroisoquinolones were obtained in up to 96% yield at room temperature under oxygen atmosphere. This transformation provides a convenient route to dihydroisoquinolones with a wide range of substrates. (Figure presented.).
Thiyl radical promoted iron-catalyzed-selective oxidation of benzylic sp3 C-H bonds with molecular oxygen
Geng, Shasha,Xiong, Baojian,Zhang, Yun,Zhang, Juan,He, Yun,Feng, Zhang
supporting information, p. 12699 - 12702 (2019/10/28)
A ligand-free iron-catalyzed method for the oxygenation of benzylic sp3 C-H bonds by molecular oxygen (1 atm) using a thiyl radical as a cocatalyst has been developed. This transformation provides a facile access to amides, esters and ketones from readily accessible corresponding amines, ethers and alkanes. It features high regioselectivity, mild oxidative conditions and excellent functional group compatibility, providing good opportunities to the site-selective functionalization of complex molecules. Preliminary mechanistic studies suggest that this reaction may not undergo a benzylic cation intermediate pathway and the carbonyl oxygen atom in the products may be derived from molecular oxygen.
C(sp3)?H Cyanation Promoted by Visible-Light Photoredox/Phosphate Hybrid Catalysis
Wakaki, Takayuki,Sakai, Kentaro,Enomoto, Takafumi,Kondo, Mio,Masaoka, Shigeyuki,Oisaki, Kounosuke,Kanai, Motomu
supporting information, p. 8051 - 8055 (2018/06/15)
Inspired by the reaction mechanism of photo-induced DNA cleavage in nature, a C(sp3)?H cyanation reaction promoted by visible-light photoredox/phosphate hybrid catalysis was developed. Phosphate radicals, generated by one-electron photooxidation of phosphate salt, functioned as a hydrogen-atom-transfer catalyst to produce nucleophilic carbon radicals from C(sp3)?H bonds with a high bond-dissociation energy. The resulting carbon radicals were trapped by a cyano radical source (TsCN) to produce the C?H cyanation products. Due to the high functional-group tolerance and versatility of the cyano group, the reaction will be useful for realizing streamlined building block syntheses and late-stage functionalization of drug-like molecules.
DDQ-promoted mild and efficient metal-free oxidative α-cyanation of N-acyl/sulfonyl 1,2,3,4-tetrahydroisoquinolines
Kim, Hong Pyo,Yu, Heesun,Kim, Hyoungsu,Kim, Seok-Ho,Lee, Dongjoo
, (2018/12/13)
A mild and highly efficient metal-free oxidative α-cyanation of N-acyl/sulfonyl 1,2,3,4-tetrahydroisoquinolines (THIQs) has been accomplished at an ambient temperature via DDQ oxidation and subsequent trapping of N-acyl/sulfonyl iminium ions with (n-Bu)s
Cobalt-Porphyrin-Catalysed Intramolecular Ring-Closing C?H Amination of Aliphatic Azides: A Nitrene-Radical Approach to Saturated Heterocycles
Kuijpers, Petrus F.,Tiekink, Martijn J.,Breukelaar, Willem B.,Broere, Dani?l L. J.,van Leest, Nicolaas P.,van der Vlugt, Jarl Ivar,Reek, Joost N. H.,de Bruin, Bas
supporting information, p. 7945 - 7952 (2017/06/19)
Cobalt-porphyrin-catalysed intramolecular ring-closing C?H bond amination enables direct synthesis of various N-heterocycles from aliphatic azides. Pyrrolidines, oxazolidines, imidazolidines, isoindolines and tetrahydroisoquinoline can be obtained in good to excellent yields in a single reaction step with an air- and moisture-stable catalyst. Kinetic studies of the reaction in combination with DFT calculations reveal a metallo-radical-type mechanism involving rate-limiting azide activation to form the key cobalt(III)-nitrene radical intermediate. A subsequent low barrier intramolecular hydrogen-atom transfer from a benzylic C?H bond to the nitrene-radical intermediate followed by a radical rebound step leads to formation of the desired N-heterocyclic ring products. Kinetic isotope competition experiments are in agreement with a radical-type C?H bond-activation step (intramolecular KIE=7), which occurs after the rate-limiting azide activation step. The use of di-tert-butyldicarbonate (Boc2O) significantly enhances the reaction rate by preventing competitive binding of the formed amine product. Under these conditions, the reaction shows clean first-order kinetics in both the [catalyst] and the [azide substrate], and is zero-order in [Boc2O]. Modest enantioselectivities (29–46 % ee in the temperature range of 100–80 °C) could be achieved in the ring closure of (4-azidobutyl)benzene using a new chiral cobalt-porphyrin catalyst equipped with four (1S)-(?)-camphanic-ester groups.
Catalytic Synthesis of N-Heterocycles via Direct C(sp3)-H Amination Using an Air-Stable Iron(III) Species with a Redox-Active Ligand
Bagh, Bidraha,Broere, Dani?l L. J.,Sinha, Vivek,Kuijpers, Petrus F.,Van Leest, Nicolaas P.,De Bruin, Bas,Demeshko, Serhiy,Siegler, Maxime A.,Van Der Vlugt, Jarl Ivar
supporting information, p. 5117 - 5124 (2017/05/04)
Coordination of FeCl3 to the redox-active pyridine-aminophenol ligand NNOH2 in the presence of base and under aerobic conditions generates FeCl2(NNOISQ) (1), featuring high-spin FeIII and an NNOISQ radical ligand. The complex has an overall S = 2 spin state, as deduced from experimental and computational data. The ligand-centered radical couples antiferromagnetically with the Fe center. Readily available, well-defined, and air-stable 1 catalyzes the challenging intramolecular direct C(sp3)-H amination of unactivated organic azides to generate a range of saturated N-heterocycles with the highest turnover number (TON) (1 mol% of 1, 12 h, TON = 62; 0.1 mol% of 1, 7 days, TON = 620) reported to date. The catalyst is easily recycled without noticeable loss of catalytic activity. A detailed kinetic study for C(sp3)-H amination of 1-azido-4-phenylbutane (S1) revealed zero order in the azide substrate and first order in both the catalyst and Boc2O. A cationic iron complex, generated from the neutral precatalyst upon reaction with Boc2O, is proposed as the catalytically active species.
