942-13-2Relevant articles and documents
Metal-free carbonylations by photoredox catalysis
Majek, Michal,Von Wangelin, Axel Jacobi
supporting information, p. 2270 - 2274 (2015/02/19)
The synthesis of benzoates from aryl electrophiles and carbon monoxide is a prime example of a transition-metalcatalyzed carbonylation reaction which is widely applied in research and industrial processes. Such reactions proceed in the presence of Pd or Ni catalysts, suitable ligands, and stoichiometric bases. We have developed an alternative procedure that is free of any metal, ligand, and base. The method involves a redox reaction driven by visible light and catalyzed by eosin Y which affords alkyl benzoates from arene diazonium salts, carbon monoxide, and alcohols under mild conditions. Tertiary esters can also be prepared in high yields. DFT calculations and radical trapping experiments support a catalytic photoredox pathway without the requirement for sacrificial redox partners.
Pd-catalyzed aldehyde to ester conversion: A hydrogen transfer approach
Tschaen, Brittany A.,Schmink, Jason R.,Molander, Gary A.
supporting information, p. 500 - 503 (2013/04/11)
Aliphatic and aromatic aldehydes are successfully converted into their corresponding esters using Pd(OAc)2 and XPhos. This approach utilizes a hydrogen transfer protocol: concomitant reduction of acetone to isopropanol provides an inexpensive and sustainable approach that mitigates the need for other oxidants.
Synthesis of the C19 methyl ether of aspercyclide A via germyl-Stille macrocyclisation and ELISA evaluation of both enantiomers following optical resolution
Carr, James L.,Sejberg, Jimmy J. P.,Saab, Fabienne,Holdom, Mary D.,Davies, Anna M.,White, Andrew J. P.,Leatherbarrow, Robin J.,Beavil, Andrew J.,Sutton, Brian J.,Lindell, Stephen D.,Spivey, Alan C.
, p. 6814 - 6824 (2011/11/14)
Aspercyclide A (1) is a biaryl ether containing 11-membered macrocyclic natural product antagonist of the human IgE-FcεRI protein-protein interaction (PPI); a key interaction in the signal transduction pathway for allergic disorders such as asthma. Herein
Rhenium complex-catalyzed acylative cleavage of ethers with acyl chlorides
Umeda, Rui,Nishimura, Takashi,Kaiba, Kenta,Tanaka, Toshimasa,Takahashi, Yuuki,Nishiyama, Yutaka
experimental part, p. 7217 - 7221 (2011/10/08)
It was found that rhenium complex was an efficient catalyst for the acylative cleavage of C-O bond of ethers with acyl chlorides. When acyclic ethers were allowed to react with acyl chlorides in the presence of a catalytic amount of ReBr(CO)5, acylative cleavage of C-O bond of acyclic ethers smoothly proceeded to give the corresponding esters in moderate to good yields. Similarly, cyclic ethers were acylative cleaved by acyl chlorides to give the corresponding chloro substituted esters in good yields by the use of Re 2O7 catalyst.
A flow microreactor system enables organolithium reactions without protecting alkoxycarbonyl groups
Nagaki, Aiichiro,Kim, Heejin,Moriwaki, Yuya,Matsuo, Chika,Yoshida, Jun-Ichi
supporting information; experimental part, p. 11167 - 11177 (2010/11/04)
A flow microreactor system consisting of micromixers and microtube reactors provides an effective tool for the generation and reactions of aryllithiums bearing an alkoxycarbonyl group at para-, meta-, and ortho-positions. Alkyl p- and m-lithiobenzoates were generated by the I/Li exchange reaction with PhLi. The Br/Li exchange reactions with sBuLi were unsuccessful. Subsequent reactions of the resulting aryllithiums with electrophiles gave the desired products in good yields. On the other hand, alkyl o-lithiobenzoates were successfully generated by the Br/ Li exchange reaction with sBuLi. Subsequent reactions with electrophiles gave the desired products in good yields.
Aryllithium compounds bearing alkoxycarbonyl groups: Generation and reactions using a microflow system
Nagaki, Aiichiro,Kim, Heejin,Yoshida, Jun-Ichi
supporting information; experimental part, p. 7833 - 7836 (2009/04/10)
Go with the flow: An effective method for the generation and reaction of aryllithium compounds bearing an alkoxycarbonyl group is developed using microflow systems with very short residence times together with fast mixing and efficient temperature control. A wide range of alkoxycarbonyl groups including ethoxycarbonyl and methoxycarbonyl groups are tolerant of the microflow conditions. (Chemical Equation Presented)
Alkoxycarbonylation of aryl iodides using gaseous carbon monoxide and pre-pressurized reaction vessels in conjunction with microwave heating
Kormos, Chad M.,Leadbeater, Nicholas E.
, p. 65 - 68 (2008/03/14)
The microwave-promoted alkoxycarbonylation of aryl iodides using reaction vessels pre-pressurized with carbon monoxide is reported. Reactions are performed using 0.1 mol% palladium acetate as catalyst, DBU as base and are complete within 20-30 min. A range of aryl iodide substrates can be converted to the corresponding esters using this methodology. Primary and secondary alcohols work well whereas a tertiary alcohol substrate proves less reactive. The potential for scale-up of the reaction has also been explored. The Royal Society of Chemistry.
Alkoxycarbonylation reactions performed using near-stoichiometric quantities of CO
Kormos, Chad M.,Leadbeater, Nicholas E.
, p. 2006 - 2010 (2008/02/09)
Alkoxycarbonylation reactions using near-stoichiometric quantities of carbon monoxide gas are presented. The reactions are performed using microwave heating which, as well as the inherent advantages of rate acceleration, offers a convenient method for loading vessels with gases. Georg Thieme Verlag Stuttgart.
Scope and mechanistic insights into the use of tetradecyl(trihexyl) phosphonium bistriflimide: A remarkably selective ionic liquid solvent for substitution reactions
McNulty, James,Nair, Jerald J.,Cheekoori, Sreedhar,Larichev, Vladimir,Capretta, Alfredo,Robertson
, p. 9314 - 9322 (2007/10/03)
A survey of substitution reactions conducted in a phosphonium bistriflimide ionic liquid is presented. The results demonstrate high selectivity favoring substitution over typically competitive elimination and solvolytic processes even when challenging secondary and tertiary electrophiles are employed. The first reports of Kornblum substitution reactions in an ionic liquid are described that proceed with very high chemoselectivity in favor of nitro over nitroso products and elimi nation side products. The structure-reactivity study indicates that these reactions proceed through a narrow spectrum of pathways ranging from straight SN2 to a preassociation pathway along a saddle point that approaches the SN1 limit. The barrier to the formation of dissociated carbocations is attributed to the structural features of this ionic liquid that favor intervention of the associated nucleophile over dissociation, also preventing cross over to E1 processes. The lack of any basic entity in the phosphonium bistriflimide ionic liquid appears to prevent any potential base-mediated elimination reactions, which makes this a highly selective medium for use in general substitution reactions.
