91633-30-6Relevant academic research and scientific papers
Photoacid-Enabled Synthesis of Indanes via Formal [3 + 2] Cycloaddition of Benzyl Alcohols with Olefins
Yang, Biao,Dong, Kui,Li, Xiang-Sheng,Wu, Li-Zhu,Liu, Qiang
, p. 2040 - 2044 (2022/03/17)
An environmentally friendly and highly diastereoselective method for synthesizing indanes has been developed via a metastable-state photoacid system containing catalytic protonated merocyanine (MEH). Under visible-light irradiation, MEH yields a metastable spiro structure and liberated protons, which facilitates the formation of carbocations from benzyl alcohols, thus delivering diverse molecules in the presence of various nucleophiles. Mainly, a variety of indanes could be easily obtained from benzyl alcohols and olefins, and water is the only byproduct.
Mangana(iii/iv)electro-catalyzed C(sp3)-H azidation
Meyer, Tjark H.,Samanta, Ramesh C.,Del Vecchio, Antonio,Ackermann, Lutz
, p. 2890 - 2897 (2021/03/14)
Manganaelectro-catalyzed azidation of otherwise inert C(sp3)-H bonds was accomplished using most user-friendly sodium azide as the nitrogen-source. The operationally simple, resource-economic C-H azidation strategy was characterized by mild reaction conditions, no directing group, traceless electrons as the sole redox-reagent, Earth-abundant manganese as the catalyst, high functional-group compatibility and high chemoselectivity, setting the stage for late-stage azidation of bioactive compounds. Detailed mechanistic studies by experiment, spectrophotometry and cyclic voltammetry provided strong support for metal-catalyzed aliphatic radical formation, along with subsequent azidyl radical transfer within a manganese(iii/iv) manifold.
Site-Selective Copper-Catalyzed Azidation of Benzylic C-H Bonds
Suh, Sung-Eun,Chen, Si-Jie,Mandal, Mukunda,Guzei, Ilia A.,Cramer, Christopher J.,Stahl, Shannon S.
supporting information, p. 11388 - 11393 (2020/07/21)
Site selectivity represents a key challenge for non-directed C-H functionalization, even when the C-H bond is intrinsically reactive. Here, we report a copper-catalyzed method for benzylic C-H azidation of diverse molecules. Experimental and density functional theory studies suggest the benzyl radical reacts with a CuII-azide species via a radical-polar crossover pathway. Comparison of this method with other C-H azidation methods highlights its unique site selectivity, and conversions of the benzyl azide products into amine, triazole, tetrazole, and pyrrole functional groups highlight the broad utility of this method for target molecule synthesis and medicinal chemistry.
Manganese-Catalyzed Oxidative Azidation of C(sp3)-H Bonds under Electrophotocatalytic Conditions
Niu, Linbin,Jiang, Chongyu,Liang, Yuwei,Liu, Dingdong,Bu, Faxiang,Shi, Renyi,Chen, Hong,Chowdhury, Abhishek Dutta,Lei, Aiwen
supporting information, p. 17693 - 17702 (2020/11/12)
The selective installation of azide groups into C(sp3)-H bonds is a priority research topic in organic synthesis, particularly in pharmaceutical discovery and late-stage diversification. Herein, we demonstrate a generalized manganese-catalyzed oxidative azidation methodology of C(sp3)-H bonds using nucleophilic NaN3 as an azide source under electrophotocatalytic conditions. This approach allows us to perform the reaction without the necessity of adding an excess of the substrate and successfully avoiding the use of stoichiometric chemical oxidants such as iodine(III) reagent or NFSI. A series of tertiary and secondary benzylic C(sp3)-H, aliphatic C(sp3)-H, and drug-molecule-based C(sp3)-H bonds in substrates are well tolerated under our protocol. The simultaneous gram-scale synthesis and the ease of transformation of azide to amine collectively advocate for the potential application in the preparative synthesis. Good reactivity of the tertiary benzylic C(sp3)-H bond and selectivity of the tertiary aliphatic C(sp3)-H bond in substrates to incorporate nitrogen-based functionality at the tertiary alkyl group also provide opportunities to manipulate numerous potential medicinal candidates. We anticipate our synthetic protocol, consisting of metal catalysis, electrochemistry, and photochemistry, would provide a new sustainable option to execute challenging organic synthetic transformations.
B(C6F5)3-catalyzed synthesis of benzylic azides
Wrigley, Michael S.,Barker, Timothy J.
, p. 1771 - 1776 (2017/09/23)
B(C6F5)3 was found to catalyze the reaction between trimethylsilyl azide and benzylic acetates. Secondary and tertiary benzylic acetates were competent substrates in this reaction providing the azide products in moderate t
Recyclable zinc (II) ionic liquid catalyzed synthesis of azides by direct azidation of alcohols using trimethylsilylazide at room temperature
Singh, Ashima,Singh, Harjinder,Khurana
supporting information, p. 2498 - 2502 (2017/05/31)
A new efficient method has been reported for the synthesis of azides by direct azidation of alcohols with TMSN3 in presence of recyclable task specific ionic liquid (TSIL) [bmim]ZnCl3 as a catalyst in DCM at room temperature. Ionic liquid [bmim]ZnCl3 was synthesized under solvent free conditions and characterized by IR, 1H NMR, 13C NMR and HRMS. The Lewis acidity of catalyst was also examined using IR spectroscopy. The main features of this new methodology are high yields of products, recyclability of catalyst, scalability of reaction to gram scale and short reaction time.
Chemoselective, Isomerization-Free Synthesis of N-Acylketimines from N–H Imines
Kwon, Yearang,Rhee, Young Ho,Park, Jaiwook
supporting information, p. 1503 - 1507 (2017/05/05)
N-Acylketimines were synthesized through a ruthenium-catalyzed generation of N–H ketimines from secondary azides and subsequent acylation with mixed anhydrides under mild conditions. The synthetic scope was broad to give N-acylimines having various functi
Direct Conversion of Aldehydes and Ketones into Azides by Sequential Nucleophilic Addition and Substitution
Goswami, Pratik P.,Suding, Victoria P.,Carlson, Angela S.,Topczewski, Joseph J.
supporting information, p. 4805 - 4809 (2016/10/13)
This report describes the direct conversion of aldehydes and ketones into alkyl azides by the addition of common organometallic reagents and tandem conversion of the resulting alkoxides without isolation of the intermediate alcohols. A wide range of aldehydes and organometallic reagents (R–Li or R–MgX) are suitable participants in this process. Additional reaction telescoping beyond azide formation is demonstrated.
Highly selective direct azidation of alcohols over a heterogeneous povidone-phosphotungstic solid acid catalyst
Kamble, Sumit,More, Sagar,Rode, Chandrashekhar
, p. 10240 - 10245 (2016/12/06)
A simple protocol for the selective azidation of alcohols is developed using a solid acid hybrid of a povidone and phosphotungstic acid (PVP-PWA) using azidotrimethylsilane as an azide source at room temperature. In a broad substrate scope, various activated as well as unactivated benzylic and diphenyl alcohols were treated smoothly with TMS-N3 to selectively produce only azide products with excellent yields in a very short reaction time of 2 h. FT-IR confirmed the stability of the catalyst with retention of the Keggins structure after the reaction. Recycling experiments demonstrated the reusability of the PVP-PWA (3?:?1) several times without losing its original activity.
Convenient and direct azidation of sec -benzyl alcohols by trimethylsilyl azide with bismuth(III) triflate catalyst
Tummatorn, Jumreang,Thongsornkleeb, Charnsak,Ruchirawat, Somsak,Thongaram, Phanida,Kaewmee, Benyapa
, (2015/01/30)
Sec-Benzyl azides were efficiently prepared by bismuth(III)-catalyzed direct azidation of sec-benzyl alcohols. The reaction was applied to a variety of substrates to provide the desired products in up to 99% yield within a short reaction time.
