73930-98-0Relevant academic research and scientific papers
Synthesis of Indoles by Reductive Cyclization of Nitro Compounds Using Formate Esters as CO Surrogates
Ahmed Fouad, Manar,Ferretti, Francesco,Formenti, Dario,Milani, Fabio,Ragaini, Fabio
supporting information, p. 4876 - 4894 (2021/09/20)
Alkyl and aryl formate esters were evaluated as CO sources in the Pd- and Pd/Ru-catalyzed reductive cyclization of 2-nitrostyrenes to give indoles. Whereas the use of alkyl formates requires the presence of a ruthenium catalyst such as Ru3(CO)12, the reaction with phenyl formate can be performed by using a Pd/phenanthroline complex alone. Phenyl formate was found to be the most effective CO source and the desired products were obtained in excellent yields, often higher than those previously reported using pressurized CO. The reaction tolerates many functional groups, including sensitive ones like a free aldehydic group or a pendant pyrrole. Detailed experiments and kinetic studies allow to conclude that the activation of phenyl formate is base-catalyzed and that the metal doesn't play a role in the decarbonylation step. The reactions can be performed in a single thick-walled glass tube with as little as 0.2 mol-% palladium catalyst and even on a 2 g scale. The same protocol can be extended to other nitro compounds, affording different heterocycles.
Ionic diamine rhodium complex catalyzed reductive N-heterocyclization of 2-nitrovinylarenes
Okuro, Kazumi,Gurnham, Joanna,Alper, Howard
experimental part, p. 4715 - 4720 (2011/07/08)
Ionic diamine rhodium complex (1) catalyzes the reductive N-cyclization of 2-vinylnitroarenes using carbon monoxide as a reducing agent to afford functionalized indoles. The catalytic system allows direct access to indoles with ester and ketone groups at the 2- or 3-position, in good yields.
Silica gel-mediated rearrangement of allylic acetates. Application to the synthesis of 1,3-enynes
Serra-Muns, Anna,Guerinot, Amandine,Reymond, Sebastien,Cossy, Janine
supporting information; experimental part, p. 4178 - 4180 (2010/08/07)
Silica gel was found to efficiently promote the rearrangement of allylic acetates into their most stable regioisomers under microwave irradiation. The reaction is easy to perform and eco-friendly. This method was applied to the metal-free synthesis of 1,3-enynes.
PdII-catalyzed highly selective arylation of allyl esters via C-H functionalization of unreactive arenes with retention of the traditional leaving group
Pan, Delin,Yu, Miao,Chen, Wei,Jiao, Ning
experimental part, p. 1090 - 1093 (2011/07/08)
A highly selective Fujiwara-Moritani oxidative Heck reaction of allyl esters with unreactive arenes via C - H bond activation was developed, in which -H elimination is highly chemo-, regio- and stereoselective. Moreover, even electron-deficient arenes are tolerated in this type of C - H activation. 2010 Wiley-VCH Verlag GmbH Co. KGaA, Weinheim.
Scandium(III) trifluoromethanesulfonate catalyzed aromatic nitration with inorganic nitrates and acetic anhydride
Kawada, Atsushi,Takeda, Shigemitsu,Yamashita, Kazumi,Abe, Hitoshi,Harayama, Takashi
, p. 1060 - 1065 (2007/10/03)
The rare earth metal(III) trifluoromethanesulfonate (rare earth metal(III) triflate, RE(OTf)3) was found to be an efficient catalyst for aromatic nitration with carboxylic anhydride-inorganic nitrate as the nitrating agent. In the presence of a catalytic amount of RE(OTf)3, the nitration of substituted benzenes proceeded to afford the corresponding nitrobenzenes. Especially, scandium(III) trifluoromethanesulfonate (scandium(III) triflate, Sc(OTf)3) is the most active catalyst among our tested Lewis acids. It was also found that acetic anhydride-Al(NO 3) · 9H2O is the most active nitrating agent in this system.
