84392-23-4Relevant academic research and scientific papers
Electrochemical Decarboxylative Cyclization of α-Amino-Oxy Acids to Access Phenanthridine Derivatives
Zhan, Yanling,Dai, Changhui,Zhu, Zitong,Liu, Ping,Sun, Peipei
supporting information, (2022/02/07)
Phenanthridines are a class of useful heterocycles in the field of drug development. In this work, a method via electrochemical decarboxylative cyclization of α-amino-oxy acids to access phenanthridine derivatives was developed. This reaction proceeded th
A Photochemical Intramolecular C-N Coupling Toward the Synthesis of Benzimidazole-Fused Phenanthridines
Bera, Shyamal Kanti,Boruah, Palash J.,Parida, Shraddha Saraswati,Paul, Amit K.,Mal, Prasenjit
, p. 9587 - 9602 (2021/07/26)
Herein, we report a direct photochemical dehydrogenative C-N coupling of unactivated C(sp2)-H and N(sp2)-H bonds. The catalysts or additive-free transformation of 2-([1,1′-biphenyl]-2-yl)-1H-benzo[d]imidazole to benzo[4,5]imidazo[1,2-f]phenanthridine was achieved at ~350 nm of irradiation via ?-hydrogen abstraction. DFT calculations helped to understand that the N-H···πinteraction was essential for the reaction to proceed at a lower energy than expected.
Biphenyl Cyclobutenone Photoelectrocyclizations
Dai, Changhang,Rainier, Jon D.,Schwartz, Zach,Song, Changqing,Zhao, Xuchen
, p. 15164 - 15176 (2021/10/20)
In this work, we demonstrate that readily available conjugated bis-aryl cyclobutenones undergo photoelectrocyclization reactions to give the corresponding dihydrophenanthrene cyclobutanones when exposed to 350 nm light, TFA, and TMSCl. We have also found that cyclobutenone electrocyclizations and cycloreversions are in equilibrium.
Metal-Free Electrochemical Coupling of Vinyl Azides: Synthesis of Phenanthridines and β-Ketosulfones
Chen, Qianjin,Kong, Xianqiang,Li, Guodong,Liang, Qi,Lin, Long,Xu, Bo,Yu, Ke
supporting information, p. 6135 - 6145 (2020/10/06)
We reported an efficient and environmentally benign electrochemical synthesis of phenanthridines by oxidative coupling of vinyl azides with sodium azide or benzenesulfonyl hydrazides, for the first time. The reaction conditions are mild, and no additional metal-catalyst or exogenous oxidants are needed. The protocol has broad substrate scope and high functional group tolerance. Furthermore, this green electrochemical procedure can be readily extended to the synthesis of β-ketosulfones. Gram scale reactions further demonstrate the practicability.
Insights into the Catalytic Activity of [Pd(NHC)(cin)Cl] (NHC=IPr, IPrCl, IPrBr) Complexes in the Suzuki–Miyaura Reaction
Izquierdo, Frédéric,Zinser, Caroline,Minenkov, Yury,Cordes, David B.,Slawin, Alexandra M. Z.,Cavallo, Luigi,Nahra, Fady,Cazin, Catherine S. J.,Nolan, Steven P.
, p. 601 - 611 (2017/12/26)
The influence of C4,5-halogenation on palladium N-heterocyclic carbene complexes and their activity in the Suzuki–Miyaura reaction were investigated. Two [Pd(NHC)(cin)Cl] complexes bearing IPrCl and IPrBr ligands (IPr=1,3-bis(2,6-diisopropyl-phenyl)imidazol-2-ylidene; cin=cinnamyl) were synthesized. After determining the electronic and steric properties of these ligands, their properties were compared to those of [Pd(IPr) (cin)Cl]. The three palladium complexes were studied by using DFT calculations to delineate their behavior in the activation step leading to the putative 12-electron active catalyst. Experimentally, their catalytic activity in the Suzuki–Miyaura reaction involving a wide range of coupling partners (30 entries) at low catalyst loading was studied.
Silver-Catalyzed Tandem C=C Bond Hydroazidation/Radical Addition/Cyclization of Biphenyl Acetylene: One-Pot Synthesis of 6-Methyl Sulfonylated Phenanthridines
Tang, Jiawei,Sivaguru, Paramasivam,Ning, Yongquan,Zanoni, Giuseppe,Bi, Xihe
supporting information, p. 4026 - 4029 (2017/08/14)
A silver-catalyzed tandem carbon-carbon triple bond hydroazidation, radical addition, and cyclization of biphenyl acetylene is described under mild conditions, leading to the formation of 6-methyl sulfonylated phenanthridines in good yields. In this novel cascade reaction, most of the atoms are incorporated into the product without cleavage of the C=C bond. Mechanistic studies suggest the reaction should proceed through an iminyl radical reactive intermediate.
Catalytic oxidative cyclization of 2′-arylbenzaldehyde oxime ethers under photoinduced electron transfer conditions
Hofstra, Julie L.,Grassbaugh, Brittany R.,Tran, Quan M.,Armada, Nicholas R.,De Lijser, H. J. Peter
, p. 256 - 265 (2016/09/09)
A series of 2′-arylbenzaldehyde oxime ethers were synthesized and shown to generate the corresponding phenanthridines upon irradiation in the presence of 9,10-dicyanoanthracene in acetonitrile. Mechanistic studies suggest that the oxidative cyclization reaction sequence is initiated by an electron transfer step followed by nucleophilic attack of the aryl ring onto the nitrogen of the oxime ether. A concave downward Hammett plot is presumably the result of a change in charge distribution in the radical cation species with strongly electron-donating substituents that yields a less electrophilic nitrogen atom and a decreased amount of cyclized product. The reaction is selective (no nitrile byproduct is formed unlike other photochemical reactions involving aldoxime ethers) as well as regiospecific when using 2′-aryl groups with metasubstituents, making this reaction a useful alternative for preparing substituted phenanthridines.
The suzuki-miyaura reaction performed using a palladium-n-heterocyclic carbene catalyst and a weak inorganic base
Izquierdo, Frédéric,Corpet, Martin,Nolan, Steven P.
supporting information, p. 1920 - 1924 (2015/03/18)
N-Heterocyclic carbenes (NHCs) have been shown to be useful ligands for the Suzuki-Miyaura cross-coupling at low catalyst loadings. We now report that the commercially available and air-stable [Pd(IPr)(cin)Cl] pre-catalyst permits the formation of various functionalized biaryls from aryl chlorides and boronic acids (37 examples) under very mild conditions using a mixture of ethanol/water as solvent and an inorganic base. [Pd(IPr)(cin)Cl] permits an operationally simple Suzuki-Miyaura reaction under very mild conditions using a mixture of ethanol/water as solvent and an inorganic base.
Atom-economic threefold cross-couplings of triarylbismuth reagents with 2-halobenzaldehydes and pot-economic in situ Wittig functionalizations with phosphonium salts
Rao, Maddali L. N.,Dhanorkar, Ritesh J.
, p. 63792 - 63806 (2015/02/19)
In this paper we report an efficient pot-economic methodology for the synthesis of ortho-olefinated biaryls. This has been achieved through an atom-economic threefold cross-coupling of triarylbismuth reagents with 2-halobenzaldehydes followed by pot-economic in situ Wittig olefination. The overall process is a pot-economic straightforward synthesis of ortho-olefinated biaryls from 2-halobenzaldehydes, triarylbismuth reagents and phosphonium salts. This pot-economic approach was applied to the formal synthesis of medicinally important Eupomatilone-6.
Facile Cu(OTf)2-catalyzed preparation of 9-tosylaminofluorene derivatives from o-arylated N-tosylbenzaldimines
Yu, Xufen,Lu, Xiyan
scheme or table, p. 2076 - 2079 (2011/05/09)
The 9-tosylaminofluorene derivatives were synthesized conveniently by Cu(OTf)2-catalyzed aza-Friedel-Crafts reaction of o-arylated N-tosylbenzaldimines in high yields. This is an efficient, atom-economic, and green method.
