161117-84-6Relevant articles and documents
Expanded-ring N-heterocyclic carbenes efficiently stabilize gold(I) cations, leading to high activity in π-acid-catalyzed cyclizations
Morozov, Oleg S.,Lunchev, Andrey V.,Bush, Alexander A.,Tukov, Aleksandr A.,Asachenko, Andrey F.,Khrustalev, Victor N.,Zalesskiy, Sergey S.,Ananikov, Valentine P.,Nechaev, Mikhail S.
, p. 6162 - 6170 (2014)
A series of six- and seven-membered expanded-ring N-heterocyclic carbene (er-NHC) gold(I) complexes has been synthesized using different synthetic approaches. Complexes with weakly coordinating anions [(er-NHC)AuX] (X -=BF4-, NTf2-, OTf -) were generated in solution. According to their 13C NMR spectra, the ionic character of the complexes increases in the order X -=Cl-2--4-. Additional factors for stabilization of the cationic complexes are expansion of the NHC ring and the attachment of bulky substituents at the nitrogen atoms. These er-NHCs are bulkier ligands and stronger electron donors than conventional NHCs as well as phosphines and sulfides and provide more stabilization of [(L)Au+] cations. A comparative study has been carried out of the catalytic activities of five-, six-, and seven-membered carbene complexes [(NHC)AuX], [(Ph3P)AuX], [(Me2S)AuX], and inorganic compounds of gold in model reactions of indole and benzofuran synthesis. It was found that increased ionic character of the complexes was correlated with increased catalytic activity in the cyclization reactions. As a result, we developed an unprecedentedly active monoligand cationic [(THD-Dipp)Au]BF4 (1,3-bis(2,6-diisopropylphenyl) -3,4,5,6-tetrahydrodiazepin-2-ylidene gold(I) tetrafluoroborate) catalyst bearing seven-membered-ring carbene and bulky Dipp substituents. Quantitative yields of cyclized products were attained in several minutes at room temperature at 1 mol% catalyst loadings. The experimental observations were rationalized and fully supported by DFT calculations. What a difference a ring makes: Expanded-ring N-heterocyclic carbenes (er-NHC) surpass their five-membered ring counterparts, as well as Ph3P and Me2S, in the stabilization of cationic gold(I) species due to increased steric protection and electron-donating properties. A monoligand cationic [(THD-Dipp)Au]BF 4 (Dipp=2,6-diisopropylphenyl) complex bearing a seven-membered ring carbene and bulky Dipp substituents exhibits unprecedentedly high catalytic activity in indole and benzofuran synthesis (see scheme).
Acid-Promoted Expeditious Syntheses of Aminated Dibenzosultams via Palladium/Norbornene Cooperatively Catalysed C?H Amination/Arylation
Zhao, Shen,Han, Shibo,Du, Guopeng,Zhang, Daopeng,Liu, Hui,Li, Xinjin,Dong, Yunhui,Sun, Feng-Gang
supporting information, p. 2078 - 2083 (2021/03/01)
Herein we reported a protocol to access aminated benzofused sultams through sequential ortho-amination, followed by ipso-arylation of aryl iodide bearing sulfonamide functional group via palladium/norbornene coorperative catalysis. This reaction has showcased a broad spectrum of substrate scope under mild conditions with moderate to good efficiency. (Figure presented.).
Method for preparing amine compound by alkali-catalyzed decarboxylation (by machine translation)
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Paragraph 0033, (2020/03/25)
The method is simple and convenient (reaction conditions ;), more stable,atom utilization rate, by-products are only carbon dioxide pollution, and the yield can reach. suitable for industrial production Curtis; and the method, Lossen is suitable for industrial production . The method disclosed by the invention is simple and convenient to operate under the action of a base as, rearrangement, rearrangement reaction of an alkyl, aryl or heterocyclic aromatic carboxylic acid or an ester and hydroxylamine compound, 90%. (by machine translation)
