64222-81-7Relevant academic research and scientific papers
Metal-free regioselective C-H amination for the synthesis of pyrazole-containing 2H-indazoles
Wang, Kai,Wei, Tingting,Zhang, Yujia,Hou, Jiahao,Bai, Renren,Xie, Yuanyuan
, p. 1787 - 1794 (2021/03/14)
A general and practical regioselective approach for the C-H amination of 2H-indazoles under transition-metal-free conditions was developed. A series of substrates were tested showing eminent functional group tolerance and affording the C-N functionalization products in good to excellent yields. Mechanism studies revealed that a radical process was involved in this transformation.
Dearomative Photocatalytic Construction of Bridged 1,3-Diazepanes
Dixon, Darren J.,Duarte, Fernanda,Leitch, Jamie A.,Rogova, Tatiana
supporting information, p. 4121 - 4130 (2020/02/05)
The construction of diverse sp3-rich skeletal ring systems is of importance to drug discovery programmes and natural product synthesis. Herein, we report the photocatalytic construction of 2,7-diazabicyclo[3.2.1]octanes (bridged 1,3-diazepanes) via a reductive diversion of the Minisci reaction. The fused tricyclic product is proposed to form via radical addition to the C4 position of 4-substituted quinoline substrates, with subsequent Hantzsch ester-promoted reduction to a dihydropyridine intermediate which undergoes in situ two-electron ring closure to form the bridged diazepane architecture. A wide scope of N-arylimine and quinoline derivatives was demonstrated and good efficiency was observed in the construction of sterically congested all-carbon quaternary centers. Computational and experimental mechanistic studies provided insights into the reaction mechanism and observed regioselectivity/diastereoselectivity.
Visible-light-induced regioselective cross-dehydrogenative coupling of 2 H-indazoles with ethers
Singsardar, Mukta,Laru, Sudip,Mondal, Susmita,Hajra, Alakananda
, p. 4543 - 4550 (2019/04/30)
A visible-light-promoted regioselective C(sp2)-H/C(sp3)-H cross-dehydrogenative coupling between 2H-indazoles and ethers has been achieved using a catalytic amount of rose bengal as an organophotoredox-catalyst and tert-butyl hydroperoxide (TBHP) as an oxidant at ambient temperature under aerobic conditions. A variety of C-3 oxyalkylated 2H-indazoles have been synthesized in moderate to good yields. Mechanistic studies suggest a radical pathway of the present reaction.
Substituent effects on the stretching vibration of C═N in multi-substituted benzylideneanilines
Wang, Linyan,Cao, Chaotun,Cao, Chenzhong
supporting information, (2019/05/29)
Forty-nine samples of 3,4′/4,3′/3,3′-disubstituted benzylideneanilines (XBAYs) and 52 samples of multi-substituted XBAYs were synthesized, and their infrared absorption spectra were recorded in this paper. On the basis of the stretching vibration frequencies νC═N of C═N bridging bond of 158 samples of substituted XBAYs (including 57 samples of 4,4′-disubstituted XBAYs from reference and 101 samples of substituted XBAYs synthesized in this paper), an extensional research of substituent effects on the νC═N values from 4,4′-disubstituted XBAYs to multi-substituted XBAYs was made. A modified equation for quantifying the νC═N values of multi-substituted XBAYs was obtained (shown as Equation (3)). Equation (3) indicates that the excited-state substituent constant of Y and the substituent specific cross-interaction effect between X and X cannot be ignored for the quantitative regression analysis of the νC═N values of multi-substituted XBAYs. Compared with Equation (1), Equation (3) has a wider application and more accuracy in quantifying the νC═N values of substituted XBAYs.
One-pot sequential multicomponent reaction between: In situ generated aldimines and succinaldehyde: Facile synthesis of substituted pyrrole-3-carbaldehydes and applications towards medicinally important fused heterocycles
Singh, Anoop,Mir, Nisar A.,Choudhary, Sachin,Singh, Deepika,Sharma, Preetika,Kant, Rajni,Kumar, Indresh
, p. 15448 - 15458 (2018/05/03)
An efficient sequential multi-component method for the synthesis of N-Arylpyrrole-3-carbaldehydes has been developed. This reaction involved a proline-catalyzed direct Mannich reaction-cyclization sequence between succinaldehyde and in situ generated Ar/H
A Rhodium-Catalyzed [3 + 2] Annulation of General Aromatic Aldimines/Ketimines and N-Substituted Maleimides
Zhu, Chengfeng,Luan, Jichao,Fang, Jun,Zhao, Xu,Wu, Xiang,Li, Yougui,Luo, Yunfei
supporting information, (2018/09/27)
A new class of rhodium-catalyzed, C-H activation triggered [3 + 2] annulations of aromatic aldimines or ketimines and maleimides was reported in this study. A broad scope of general imines without electron-withdrawing groups were successfully activated an
A Rhodium-Catalyzed [3 + 2] Annulation of General Aromatic Aldimines/Ketimines and N-Substituted Maleimides
Zhu, Chengfeng,Luan, Jichao,Fang, Jun,Zhao, Xu,Wu, Xiang,Li, Yougui,Luo, Yunfei
supporting information, p. 5960 - 5963 (2018/09/29)
A new class of rhodium-catalyzed, C-H activation triggered [3 + 2] annulations of aromatic aldimines or ketimines and maleimides was reported in this study. A broad scope of general imines without electron-withdrawing groups were successfully activated an
Asymmetric Petasis Borono-Mannich Allylation Reactions Catalyzed by Chiral Biphenols
Jiang, Yao,Schaus, Scott E.
supporting information, p. 1544 - 1548 (2017/02/05)
Chiral biphenols catalyze the asymmetric Petasis borono-Mannich allylation of aldehydes and amines through the use of a bench-stable allyldioxaborolane. The reaction proceeds via a two-step, one-pot process and requires 2–8 mole % of 3,3′-Ph2-BINOL as the optimal catalyst. Under microwave heating the reaction affords chiral homoallylic amines in excellent yields (up to 99 %) and high enantioselectivies (er up to 99:1). The catalytic reaction is a true multicomponent condensation reaction whereas both the aldehyde and the amine can possess a wide range of structural and electronic properties. Use of crotyldioxaborolane in the reaction results in stereodivergent products with anti- and syn-diastereomers both in good diastereoselectivities and enantioselectivities from the corresponding E- and Z-borolane stereoisomers.
Paclitaxel Biosynthesis: Adenylation and Thiolation Domains of an NRPS TycA PheAT Module Produce Various Arylisoserine CoA Thioesters
Muchiri, Ruth,Walker, Kevin D.
, p. 1415 - 1425 (2017/03/23)
Structure-activity relationship studies show that the phenylisoserinyl moiety of paclitaxel (Taxol) is largely necessary for the effective anticancer activity. Several paclitaxel analogues with a variant isoserinyl side chain have improved pharmaceutical
One-Pot Catalytic Approach for the Selective Aerobic Synthesis of Imines from Alcohols and Amines Using Efficient Arene Diruthenium(II) Catalysts under Mild Conditions
Saranya, Sundar,Ramesh, Rengan,Grzegorz Ma?ecki, Jan
, p. 6726 - 6733 (2017/12/07)
A green and efficient catalytic approach for the selective synthesis of imines in air at room temperature was achieved with the aid of newly synthesised diruthenium(II) complexes [(η6-p-cymene)2Ru2Cl2(μ-L)] containing substituted 1,2-diacylhydrazine ligands. All the new complexes were fully characterised by analytical and spectroscopic techniques. The solid-state structure of a representative complex was solved by single-crystal X-ray diffraction analysis. The diruthenium(II) complexes also enable the selective aerobic oxidation of alcohols to aldehydes. The catalytic reaction operates in the presence of air as a green and cheap oxidant, and releases water as the only by-product. A plausible mechanism is proposed for the imine formation, which is believed to proceed via an aldehyde intermediate.
