1807-69-8Relevant academic research and scientific papers
Iridium(III)-Catalyzed C(3)-H Alkylation of Isoquinolines via Metal Carbene Migratory Insertion
Jha, Neha,Singh, Roushan Prakash,Saxena, Paridhi,Kapur, Manmohan
, p. 8694 - 8698 (2021/11/24)
An Ir(III)-catalyzed C(3)-H alkylation of N-acetyl-1,2-dihydroisoquinolines with diverse acceptor-acceptor diazo compounds has been achieved under a single catalytic system via metal carbene migratory insertion. Moreover, further synthetic transformations of the alkylated products such as aromatization, selective decarboxylation, and decarbonylation lead to the formation of several synthetically viable isoquinoline derivatives having immense potentials.
One-pot preparation of methyl 2-diazo-3-oxopropionates comprising an aqueous ‘sulfonyl-azide-free’ (SAFE) diazo transfer step
Bakulina, Olga Yu.,Dar'in, Dmitry V.,Krasavin, Mikhail,Zhmurov, Petr A.
, p. 311 - 312 (2020/06/10)
Methyl 2-diazo-3-oxopropionates were obtained by in situ methoxycarbonylation of methyl ketones followed by diazo transfer onto active methylene group of the intermediate β-oxo esters. At the second stage, ‘sulfonyl-azide-free’ (SAFE) diazo transfer proto
One-pot synthesis of β-O-4 lignin models: Via the insertion of stable 2-diazo-1,3-dicarbonyls into O-H bonds
Burtoloso, Antonio C. B.,De Oliveira, Gabriela P.,Dias, Rafael Mafra P.
, p. 4815 - 4823 (2020/07/13)
Because lignin is a macromolecule that is a sustainable source of aromatic compounds, model substrates are commonly used to increase our understanding of its complex structure. However, few methods have been described for the synthesis of these models. Herein, we describe a new route towards the synthesis of β-O-4 lignin models by intermolecular O-H insertion reactions with simple and stable diazocarbonyls. The benefits of this developed method were shorter reaction times and high yields, as well as mild and environmentally friendly conditions. This journal is
Atroposelective Phosphoric Acid Catalyzed Three-Component Cascade Reaction: Enantioselective Synthesis of Axially Chiral N-Arylindoles
Wang, Lei,Zhong, Jialing,Lin, Xufeng
supporting information, p. 15824 - 15828 (2019/10/28)
An efficient organocatalytic atroposelective three-component cascade reaction of 2,3-diketoesters, aromatic amines, and 1,3-cyclohexanediones has been developed for the highly enantioselective synthesis of axially chiral N-arylindoles. The success of this method derives from the use of a newly developed second-generation chiral spirocyclic phosphoric acid as the catalyst. In addition, this protocol was extended to the synthesis of an axially chiral monophosphorus ligand.
α-Alkylidene-γ-butyrolactone Formation via Bi(OTf)3-Catalyzed, Dehydrative, Ring-Opening Cyclizations of Cyclopropyl Carbinols: Understanding Substituent Effects and Predicting E/Z Selectivity
Sandridge, Matthew J.,McLarney, Brett D.,Williams, Corey W.,France, Stefan
, p. 10883 - 10897 (2017/10/27)
A Bi(OTf)3-catalyzed ring-opening cyclization of (hetero)aryl cyclopropyl carbinols to form α-alkylidene-γ-butyrolactones (ABLs) is reported. This transformation represents different chemoselectivity from previous reports that demonstrated formation of (hetero)aryl-fused cyclohexa-1,3-dienes upon acid-promoted cyclopropyl carbinol ring opening. ABLs are obtained in up to 89% yield with a general preference for the E-isomers. Mechanistically, Bi(OTf)3 serves as a stable and easy to handle precursor to TfOH. TfOH then catalyzes the formation of cyclopropyl carbinyl cations, which undergo ring opening, intramolecular trapping by the neighboring ester group, subsequent hydrolysis, and loss of methanol resulting in the formation of the ABLs. The nature and relative positioning of the substituents on both the carbinol and the cyclopropane determine both chemo- and stereoselective outcomes. Carbinol substituents determine the extent of cyclopropyl carbinyl cation formation. The cyclopropane donor substituents determine the overall reaction chemoselectivity. Weakly stabilizing or electron-poor donor groups provide better yields of the ABL products. In contrast, copious amounts of competing products are observed with highly stabilizing cyclopropane donor substituents. Finally, a predictive model for E/Z selectivity was developed using DFT calculations.
One-pot synthesis of 2,3-difunctionalized indoles: Via Rh(III)-catalyzed carbenoid insertion C-H activation/cyclization
Lv, Honggui,Shi, Jingjing,Wu, Bo,Guo, Yujuan,Huang, Junjun,Yi, Wei
supporting information, p. 8054 - 8058 (2017/10/13)
Reported herein is the first Rh(iii)-catalyzed carbenoid insertion C-H activation/cyclization of N-arylureas and α-diazo β-keto esters. The redox-neutral reaction has the following features: good to excellent yields, broad substrate/functional group tolerance, exclusive regioselectivity, and no need for additional oxidants or additives, which render this methodology as a more efficient and versatile alternative to the existing methods for the synthesis of 2,3-difunctionalized indoles.
Synthesis of 2,3-Disubstituted NH Indoles via Rhodium(III)-Catalyzed C-H Activation of Arylnitrones and Coupling with Diazo Compounds
Guo, Xin,Han, Jianwei,Liu, Yafeng,Qin, Mingda,Zhang, Xueguo,Chen, Baohua
, p. 11505 - 11511 (2017/11/10)
A rhodium-catalyzed intermolecular coupling between arylnitrones and diazo compounds by C-H activation/[4 + 1] annulation with a C(N2)-C(acyl) bond cleavage is reported, and 2,3-disubstituted NH indoles are directly synthesized in up to a 94% yield. A variety of functional groups are applicable to this reaction to give the corresponding products with high selectivity. Compared to other previously reported Rh(III)-catalyzed synthesis of homologous series, this method is simpler, more general, and more efficient.
Addition of mixed (Alkenyl)dialkylzincates to vicinal diketo esters
Selter, Lars,Harms, Klaus,Koert, Ulrich
supporting information, p. 1215 - 1230 (2017/12/07)
Methods for the regioselective alkylation, arylation, and alkenylation of α,β-diketo esters using organozinc reagents are reported. Alkylation and arylation at the α-position is possi-ble using diorganozinc compounds. Alkenylation can be achieved using mixed (alkenyl)dineopentylzincates.
Calcium-catalyzed, dehydrative, ring-opening cyclizations of cyclopropyl carbinols derived from donor-acceptor cyclopropanes
Sandridge, Matthew J.,France, Stefan
, p. 4218 - 4221 (2016/09/09)
A calcium-catalyzed, dehydrative, ring-opening cyclization of (hetero)aryl cyclopropyl carbinols is reported. The cyclopropyl carbinols are prepared directly from the corresponding donor-acceptor (D-A) cyclopropanes. The calcium catalyst catalyzes the formation of putative (hetero)aryl cyclopropyl carbinyl cations that undergo ring-opening to allylcarbinyl cations. Subsequent intramolecular Friedel-Crafts reaction affords (hetero)aryl-fused cyclohexa-1,3-dienes in up to 97% yield. This approach represents the first example of catalysis for this intramolecular, dehydrative ring-opening cyclization and outperforms the previous reports using stoichiometric Lewis acids.
Dichlorination of α-Diazo-β-dicarbonyls using (dichloroiodo)benzene
Coffey, Keith E.,Murphy, Graham K.
supporting information, p. 1003 - 1007 (2015/05/20)
Abstract α-Diazo-β-dicarbonyl compounds were chlorinated using (dichloro)iodobenzene and an activating catalyst. A broad range of reaction rates was observed, which paralleled the relative stability/nucleo-philicity of the diazo compounds. Acyclic diazocarbonyls reacted faster than cyclics, and β-diketones were much faster to react than β-keto esters or β-diesters. Lewis acid activation was used for the first time, allowing us to overcome instances of poor chemoselectivity. Though the yields ranged from low to good, this chlorination reaction has again proven a mild and effective halogenation strategy.
