3a-(o-Nitrophenyl)octahydroindol-4-ones: Synthesis and spectroscopic analysis
摘要:
A short entry to 3a-(o-nitrophenyl)octahydroindol-4-ones employing ozonolysis and double reductive amination of 2-allyl-2-(o-nitrophenyl)-1,3-cyclohexanedione (9) is described. The symmetric dione 9 is synthesized in a 50% overall yield from 1,3-cyclohexanedione by means of o-nitroarylation followed by O-allylation and subsequent Claisen rearrangement. Configurational and conformational aspects of azabicyclic derivatives 1 (a-k) are discussed.
Direct C–H α-Arylation of Enones with ArI(O<sub>2</sub>CR)<sub>2</sub> Reagents
作者:Felipe Cesar Sousa e Silva、Nguyen T. Van、Sarah E. Wengryniuk
DOI:10.1021/jacs.9b11282
日期:2020.1.8
mediated by hypervalent iodine reagents. The reaction proceeds via a reductive iodonium Claisen rearrangement of in situ β-pyridinium silyl enol ethers. The aryl groups are derived from ArI(O2CCF3)2 reagents, which are readily accessed from the parent iodoarenes. It is tolerant of a wide range of substitution patterns and the incorporated arenes maintain the valuable iodine functional handle. Mechanistic
Synthesis of 1,2,3,4-tetrahydrocarbazoles and related tricyclic indoles
作者:Tricia L. Scott、Nicholas Burke、Grissell Carrero-Martínez、Björn C.G. Söderberg
DOI:10.1016/j.tet.2006.11.052
日期:2007.1
Reduction of 2-(2-nitrophenyl)-2-cyclohexene-1-ones using palladium on carbon under 1 atm of hydrogen gas at ambient temperature affords 1,2,3,4-tetrahydrocarbazoles in excellent isolated yields. The starting materials were prepared by intermolecular Stille coupling of 2-iodo-2-cyclohexen-1-ones with 2-(tributylstannyl)-1-nitrobenzenes.
Sequential Michael Addition/Electrophilic Alkynylation: Synthesis of α-Alkynyl-β-Substituted Ketones and Chromanones
作者:Bruno V. M. Teodoro、Luiz F. Silva
DOI:10.1021/acs.joc.8b02251
日期:2018.11.2
α-alkynyl-β-substituted cyclic ketones and analogue chromanones via one-pot Michael addition/hypervalent iodine-based α-alkynylation. Cu(I)-catalyzed Michael addition using either alkyl-aluminum or Grignard reagents, followed by diastereoselective electrophilic alkynylation of the resulting enolate by 1-ethynyl-1λ3,2-benziodoxol-3(1H)-one (EBX) resulted in the α-alkynyl-β-substituted cyclic ketones or chromanones
A Palladium-Catalyzed Ullmann Cross-Coupling/Reductive Cyclization Route to the Carbazole Natural Products 3-Methyl-9<i>H</i>-carbazole, Glycoborine, Glycozoline, Clauszoline K, Mukonine, and Karapinchamine A
作者:Qiao Yan、Emma Gin、Malgorzata Wasinska-Kalwa、Martin G. Banwell、Paul D. Carr
DOI:10.1021/acs.joc.7b00044
日期:2017.4.21
The title natural products 2–7 have been prepared by reductive cyclization of the relevant 2-arylcyclohex-2-en-1-one (e.g. 20) to the corresponding tetrahydrocarbazole and dehydrogenation (aromatization) of this to give the target carbazole (e.g. 4). Compounds such as 20 were prepared using a palladium-catalyzed Ullmann cross-coupling reaction between the appropriate 2-iodocyclohex-2-en-1-one and o-halonitrobenzene
Synthesis of Indoles via Palladium[0]-Mediated Ullmann Cross-Coupling of <i>o-</i>Halonitroarenes with α-Halo-enones or -enals
作者:Martin G. Banwell、Brian D. Kelly、Okanya J. Kokas、David W. Lupton
DOI:10.1021/ol034745w
日期:2003.7.1
[reaction: see text] Palladium[0]-mediated Ullmann cross-coupling of o-halonitrobenzene (1) and various related nitroarenes with a range of alpha-halo-enones (e.g., 2) or -enals readily affords the expected alpha-arylenones, e.g., 3, or -enals, which are converted into the corresponding indoles, e.g., 4, on reaction with dihydrogen in the presence of Pd on C.