Photoredox Minisci-Type Hydroxyfluoroalkylation of Isoquinolines with -Trifluoroethoxyphthalimide.

A straightforward photocatalytic approach has been demonstrated to incorporate a trifluoroethanol unit onto the isoquinolines. Herein, we report -trifluoroethoxyphthalimide as a hydroxyfluoroalkyl radical precursor, enabling efficient synthesis of trifluoroethanol-substituted heteroarenes. Radical quenching experiments confirmed the involvement of a free-radical pathway under developed photocatalytic conditions.

Cp*Co(III)-Catalyzed Selective C8-Olefination and Oxyarylation of Quinoline -Oxides with Terminal Alkynes.

Herein we report Cp*Co(III)-catalyzed site-selective (C8)-H olefination and oxyarylation of quinoline -oxides with terminal alkynes. The selectivity for C8-olefination and oxyarylation is sterically and electronically controlled. In the case of quinoline -oxides (unsubstituted at the C2 position), only the olefination product was obtained irrespective of the nature of the alkynes.

Predictable site-selective functionalization: Promoter group assisted -halogenation of -substituted heteroaromatics under metal-free condition.

Herein, regioselective -C-H halogenation of -pyrimidyl (hetero)aromatics through SAr (electrophilic aromatic substitution) type reaction is disclosed. SAr type reaction has been utilized for the C5-bromination of indolines (-selective) with -bromosuccinimide under metal and additive-free conditions in good to excellent yields. The developed methodology is also applicable for iodination and challenging chlorination.

Cp*Rh(III)-Catalyzed Regioselective C(sp)-H Electrophilic Trifluoromethylthiolation of 8-Methylquinolines.

Rh(III)-catalyzed regioselective trifluoromethylthiolation of the unactivated C(sp)-H bond of 8-methylquinolines with bench-stable electrophilic trifluoromethylthiolating reagent via C(sp)-H activation is explored. Various substituted 8-methylquinolines provided the products in good yields with high regioselectivity. Current reaction conditions are also applicable for the late-stage functionalization of natural molecule santonin and caffeine-substituted 8-methylquinoline.

Rh(III)-Catalyzed Regioselective C8-Alkylation of Quinoline -Oxides with Maleimides and Acrylates.

Herein, we disclose the Rh(III)-catalyzed selective C8-alkylation of quinoline -oxides with maleimides and acrylates. The main features of the reaction include complete C8-selectivity and broad substrate scope with good to excellent yields. The reaction also proceeded well with unprotected maleimide.

Co(III)-Catalyzed C-H Amidation of Nitrogen-Containing Heterocycles with Dioxazolones under Mild Conditions.

A cobalt(III)-catalyzed C-8 selective C-H amidation of quinoline -oxide using dioxazolone as an amidating reagent under mild conditions is disclosed. The reaction proceeds efficiently with excellent functional group compatibility. The utility of the current method is demonstrated by gram scale synthesis of C-8 amide quinoline -oxide and by converting this amidated product into functionalized quinolines.

Cp*Rh -Catalyzed Sterically Controlled C(sp )-H Selective Mono- and Diarylation of 8-Methylquinolines with Organoborons.

Herein, the Rh -catalyzed selective monoarylation and diarylation (symmetrical and unsymmetrical) of 8-methylquinolines with organoboron reagents are disclosed. The selective monoarylation of primary C(sp )-H bonds is achieved by using 7-substituted 8-methylquinolines or by changing the quantity of the aryl boronic acids. The method is also applicable for the arylation of 2-ethylpyridines, and the heteroarylation with thiophene-2-ylboronic acids.

Rh(III)-Catalyzed C(8)-H Activation of Quinoline -Oxides: Regioselective C-Br and C-N Bond Formation.

A highly efficient and regioselective Rh(III)-catalyzed protocol for C8-bromination and amidation of quinoline -oxide was developed. The transformation was found to be successful up to gram scale with excellent functional group tolerance and wide substrate scope. The mechanistic study revealed five-membered rhodacycle with quinoline -oxide as a key intermediate for regioselective C8-functionalization.

Catalyst-Free Synthesis of 2-Anilinoquinolines and 3-Hydroxyquinolines via Three-Component Reaction of Quinoline N-Oxides, Aryldiazonium Salts, and Acetonitrile.

A rapid microwave-assisted, catalyst-free, three-component synthesis of various 2-anilinoquinolines from quinoline N-oxides and aryldiazonium salts in acetonitrile under microwave irradiation is reported. This reaction utilizes acetonitrile as a single nitrogen source and involves the formation of two new C-N bonds via the formal [3 + 2] cycloaddition reaction. In the case of 2-substituted quinolines, 3-hydroxyquinoline was observed as the main product via a 1,3 shift of the oxygen atom from N-oxide to the C3 position of quinolines.

Evaluation of Antiplasmodial Potential of C2 and C8 Modified Quinolines: in vitro and in silico Study.

Background: Malaria remains a common life-threatening infectious disease across the globe due to the development of resistance by Plasmodium parasite against most antimalarial drugs. The situation demands new and effective drug candidates against Plasmodium.

Objectives: The objective of this study is to design, synthesize and test novel quinoline based molecules against the malaria parasite.

Metal-Free Synthesis of 2-Substituted 3-(2-Hydroxyaryl)quinolines and 4-(2-Hydroxyaryl)acridines via Benzyne Chemistry.

A metal-free approach for the synthesis of 3-aryl-2-substituted quinolines and 4-arylacridines has been developed via the 1,3-dipolar cycloaddition reactions of arynes with N-oxides. Reactions of various 2-substitued quinoline N-oxides with ortho-(trimethylsilyl)aryltriflates in the presence of KF gave 3-(2-hydroxyaryl)quinoline derivatives in good yields. Acridine N-oxides also reacted with arynes to furnish 4-(2-hydroxyaryl)acridines, albeit in moderate yields.