247-66-5Relevant academic research and scientific papers
Fast intramolecular charge transfer with a planar rigidized electron donor/acceptor molecule
Yoshihara, Toshitada,Druzhinin, Sergey I.,Zachariasse, Klaas A.
, p. 8535 - 8539 (2004)
The planar rigidized molecule fluorazene (FPP) undergoes fast reversible intramolecular charge transfer (ICT) in the excited state, with a reaction time of 12 ps in the polar solvent ethyl cyanide at -45 °C. The ICT state of FPP has a dipole moment μe(ICT) of 13 D, much larger than that of the locally excited state LE (1 D). The ICT behavior of FPP is similar to that of its flexible counterpart N-phenylpyrrole (PP), for which μe(ICT) = 12 D. These results show that intramolecular charge transfer to a planar ICT state can occur efficiently. In designing ICT systems capable of rapid switching, it is therefore important to realize that large amplitude motions such as those necessary for the formation of a twisted intramolecular charge transfer (TICT) state are not required.
Palladium-Catalyzed Formal [4 + 1] Annulation via Metal Carbene Migratory Insertion and C(sp2)-H Bond Functionalization
Xu, Shuai,Chen, Ri,Fu, Zihao,Zhou, Qi,Zhang, Yan,Wang, Jianbo
, p. 1993 - 1997 (2017/08/14)
A highly efficient and operationally simple palladium-catalyzed formal [4 + 1] annulation reaction has been developed. The reaction is featured by the formation of two different C-C bonds on a carbenic center. It represents a concise method for the synthesis of a wide range of polycyclic aromatic hydrocarbons (PAHs) and 1H-indenes with easily available (trimethylsilyl)diazomethane as the carbene source. Metal carbene migratory insertion and C(sp2)-H bond activation are proposed as the key steps in this transformation. The reaction further demonstrates the versatility of the carbene-based coupling in combination with various transition-metal-catalyzed transformations.
Intramolecular redox reaction for the synthesis of N-aryl pyrroles catalyzed by Lewis acids
Du, Hong-Jin,Zhen, Le,Wen, Xiaoan,Xu, Qing-Long,Sun, Hongbin
, p. 9716 - 9719 (2015/02/19)
An efficient approach to synthesize N-aryl pyrroles via Lewis acid-mediated 1,5-hydride shift and isomerization of 2-(3-pyrroline-1-yl)arylaldehydes has been achieved in up to 89% yield. This methodology is applicable to the synthesis of fluorazene deriva
N-fused indolines through non-carbonyl-stabilized rhodium carbenoid C-H insertion of N-aziridinyl imines
Mahoney, Stuart J.,Fillion, Eric
supporting information; experimental part, p. 68 - 71 (2012/02/04)
Under rhodium catalysis, N-aziridinyl imines provided access to N-fused indolines through non-carbonyl-stabilized rhodium carbenoid C-H insertion. The utility of this methodology for the synthesis of architecturally complex heterocycles was further demonstrated by an expedient total synthesis of ( ±)-cryptaustoline (see scheme). Copyright
Reactions of 2-(pyrrol-1-yl)benzyl radicals and related species under flash vacuum pyrolysis conditions
Cadogan,Clark, Bernard A. J.,Ford, Daniel,MacDonald, Ranald J.,MacPherson, Andrew D.,McNab, Hamish,Nicolson, Iain S.,Reed, David,Sommerville, Craig C.
experimental part, p. 5173 - 5183 (2010/04/03)
2-(Pyrrol-1-yl)phenoxyl, aminyl, thiophenoxyl and benzyl radicals 2a-2d, respectively, were generated in the gas-phase under flash vacuum pyrolysis conditions. In all cases except the phenoxyl, cyclisation took place providing acceptable synthetic routes to the fused heterocycles 11, 14 and 15, respectively. Only sigmatropic rearrangement products were isolated, in low yields, from the phenoxyl 2a. The pyrrolo[1,2-a]benzimidazole 11 adopts the 1H-tautomer exclusively in chloroform solution. Electrophilic substitution reactions of pyrrolo[2,1-b]benzothiophene 14 were studied, including protonation, deuterium exchange, Vilsmeier formylation and reaction with dimethyl acetylenedicarboxylate. 2-(2,5-Diarylpyrrol-1-yl)thiophenoxyl, phenoxyl and aminyl radicals 23a-f, were also generated in the gas-phase under similar conditions. The thiophenoxyls 23a/b gave extremely complex pyrolysate mixtures in which primary cyclisation products were formed by attack of the radical at the pyrrrole ring and attack at the ipso-, ortho- and meta- positions of the aryl ring. Secondary pyrolysis products were obtained by specific sigmatropic shifts of the N-aryl group. The 2,5-di(thien-2-yl)thiophenoxyl radical 23c gave the pyrrolobenzothiazole 31c as the only cyclisation product in low yield. FVP of the phenoxyl and aminyl radical generators 26d and 26f, respectively, gave 3-arylpyrrolo[1,2-f]phenanthridines 46d and 46f, respectively, by a hydrogen transfer-cyclisation mechanism.
Synthesis of condensed pyrroloindoles via Pd-catalyzed intramolecular C-H bond functionalization of pyrroles
Seung, Jun Hwang,Seung, Hwan Cho,Chang, Sukbok
supporting information; scheme or table, p. 16158 - 16159 (2009/05/08)
A new strategy for the synthesis of condensed hetero- or carbocycles such as pyrroloindoles or fluorenes has been developed that involves the Pd-catalyzed cyclization of readily available N-(2-halobenzyl)pyrroles or their phenyl derivatives. The reaction is proposed to proceed via oxidative addition of benzylic halides to Pd(0) followed by base-assisted C-H bond activation. A broad range of condensed cyclic products could be obtained in good to excellent yields under mild conditions. Copyright
Efficient method for the synthesis of hetarenoindanones based on 3-arylhetarenes and their conversion into hetarenoindenes
Kashulin, Igor A.,Nifant'ev, Ilya E.
, p. 5476 - 5479 (2007/10/03)
A series of hetarenoindanones have been prepared by direct double metalation of the appropriate 3-phenylhetarene with butyllithium in the presence of TMEDA followed by treatment of the resulting dilithium compound with ethyl N ,N-dimethylcarbamate. All hetarenoindanones were reduced according to Wolff-Kishner by hydrazine in the presence of KOH to the corresponding hetarenoindenes.
Intramolecular radical substitution reactions: A novel approach to fused [1,2-a]indoles
Caddick, Stephen,Aboutayab, Karim,Jenkins, Kerry,West, Robert I.
, p. 675 - 682 (2007/10/03)
A new approach to fused [1,2-a]indoles 25, 26 and 27 is described; the synthesis is based on a novel intramolecular radical cyclization reaction involving ipso-substitution using sulfone, sulfide and sulfoxide substituted indoles. Some more general aspects of scope and limitation of the process are presented including vinyl and aryl radical cyclizations of 29 and 30; investigations using substituted indoline and aniline derivatives 35 and 37 are also discussed.
Mitomycin derivatives as antileukemia agents
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, (2008/06/13)
Mitomycin derivatives having potent antitumor activity having the formula: STR1 wherein A is ON--or R4 N=N--[wherein R4 is selected from STR2 and optionally substituted heterocyclic groups (wherein R5 and R8 are
Intramolecular Nitrene Insertions into Aromatic and Heteroaromatic Systems. Part 7. Insertions into Electron-deficient Rings
Carde, Robert N.,Hayes, Peter C.,Jones, Gurnos,Cliff, Cynthya J.
, p. 1132 - 1142 (2007/10/02)
A number of routes to o-aminotriphenylmethanes are described, where one benzene ring, or both, carry potential ester groups.The most useful synthon is shown to be the 1,3-dioxan-2-yl substituent, and using this methyl 2-aminodiphenylmethane-4'-carboxylate (18) and dimethyl 2-aminotriphenylmethane-4',4''-dicarboxylate (28) have been prepared.The azides from these, respectively (19) and (29), on thermolysis at 200 deg C gave azepinoindoles (48) and (51), the first examples of ring expansion by an arylnitrene of benzene rings with electron-withdrawing substituents.Also reported are syntheses of 3- and 4-(2-azidobenzyl)pyridines (38) and (39), and of 2-(2-azidobenzyl)thiazole (40); decomposition of these azides gave mainly polymers.
