32017-70-2Relevant academic research and scientific papers
Construction of an isoquinolinone framework from carboxylic-ester-directed umpolung ring opening of methylenecyclopropanes
Wei, Hao-Zhao,Wei, Yin,Shi, Min
supporting information, p. 11201 - 11204 (2021/11/09)
An interesting type of reaction involving functionalized methylenecyclopropanes (MCPs) has been revealed. Here, a nucleophilic attack of an anionic species onto a partially polarity-reversed MCP was realized by treating a neighbouring carboxylic ester tethered to the MCP and amine with KHMDS to realize an umpolung ring opening of the MCP. This work established an operationally convenient protocol for the rapid construction of isoquinolinone frameworks. This journal is
Palladium-Catalyzed Environmentally Benign Acylation
Suchand, Basuli,Satyanarayana, Gedu
, p. 6409 - 6423 (2016/08/16)
Recent trends in research have gained an orientation toward developing efficient strategies using innocuous reagents. The earlier reported transition-metal-catalyzed carbonylations involved either toxic carbon monoxide (CO) gas as carbonylating agent or functional-group-assisted ortho sp2 C-H activation (i.e., ortho acylation) or carbonylation by activation of the carbonyl group (i.e., via the formation of enamines). Contradicting these methods, here we describe an environmentally benign process, [Pd]-catalyzed direct carbonylation starting from simple and commercially available iodo arenes and aldehydes, for the synthesis of a wide variety of ketones. Moreover, this method comprises direct coupling of iodoarenes with aldehydes without activation of the carbonyl and also without directing group assistance. Significantly, the strategy was successfully applied to the synthesis n-butylphthalide and pitofenone.
Expedient carbonylation of aryl halides in aqueous or neat condition
Ang, Wei Jie,Lo, Lee-Chiang,Lam, Yulin
, p. 8545 - 8558 (2014/12/11)
An expedient and versatile, microwave-assisted procedure for the carbonylation of aryl halides with boronic acids, alcohols or amines in water or under neat conditions has been developed. The reaction is catalyzed by fluorous, oxime-based palladacycle 1 that shows an excellent recyclable property and low levels of Pd leaching. To demonstrate the usefulness of the protocol, we applied it to the preparation of compounds of pharmaceutical interest, including a precursor of the reverse transcriptase inhibitor, niacin, benzocaine and butamben.
Acylation of Grignard reagents mediated by N-methylpyrrolidone: A remarkable selectivity for the synthesis of ketones
Gowda, Maravanhalli Sidde,Pande, Sushanth Sudhir,Ramakrishna, Ramesha Andagar,Prabhu, Kandikere Ramaiah
supporting information; experimental part, p. 5365 - 5368 (2011/09/13)
An efficient user-friendly method of acylation of Grignard reagents to selectively synthesize ketones is presented, which is assisted by simple amides such as NMP, or DMF. The present chemoselective method tolerates a variety of functional groups such as ketone, ester, nitrile and other functional groups.
Preparation of polyfunctional arylmagnesium, arylzinc, and benzylic zinc reagents by using magnesium in the presence of LiCl
Piller, Fabian M.,Metzger, Albrecht,Schade, Matthias A.,Haag, Benjamin A.,Gavryushin, Andrei,Knochel, Paul
experimental part, p. 7192 - 7202 (2010/03/05)
The presence of LiCl considerably facilitates the insertion of magnesium into various aromatic and heterocyclic bromides. Several functional groups, such as -OBoc, -OTs, -Cl, -F, -CF3, -OMe, -NMe2, and -N 2NR2, are well tolerated. The presence of a cyano group leads in some cases to competitive reduction of the organic halide to the corresponding ArH compound. The presence of sensitive groups such as methyl or ethyl ester is tolerated upon in situ trapping of the intermediate magnesium reagent with ZnCl2. This method can also be applied to the preparation of functionalized benzylic zinc reagents from benzylic chlorides. In the case of di- or tribromoaryl derivatives, directing groups such as -OPiv, -OTs, -N2NR2, or -OAc orient the zinc insertion (Zn/LiCl) to the ortho-position, while the reaction with Mg/LiCl or Mg/LiCl/ZnCl 2 leads to regioselective insertion into the para-carbon-bromine bond. Large-scale experiments (20-100 mmol) for all of the metalation procedures are described.
