232949-65-4Relevant academic research and scientific papers
Macrolactonization Reactions Driven by a Pentafluorobenzoyl Group**
Ciofini, Ilaria,Force, Guillaume,Leb?uf, David,Mayer, Robert J.,Perfetto, Anna
supporting information, p. 19843 - 19851 (2021/08/13)
Macrolactones constitute a privileged class of natural and synthetic products with a broad range of applications in the fine chemicals and pharmaceutical industry. Despite all the progress made towards their synthesis, notably from seco-acids, a macrolactonization promoter system that is effective, selective, flexible, readily available, and, insofar as possible, compatible with manifold functional groups is still lacking. Herein, we describe a strategy that relies on the formation of a mixed anhydride incorporating a pentafluorophenyl group which, due to its high electronic activation enables a convenient access to macrolactones, macrodiolides and esters with a broad versatility. Kinetic studies and DFT computations were performed to rationalize the reactivity of the pentafluorophenyl group in macrolactonization reactions.
Ambulation of Incipient Proton during Gas-Phase Dissociation of Protonated Alkyl Dihydrocinnamates
Xu, Sihang,Zhang, Yong,Errabelli, Ramu,Attygalle, Athula B.
, p. 9468 - 9479 (2015/10/12)
Upon activation in the gas phase, protonated alkyl dihydrocinnamates undergo an alcohol loss. However, the mechanism followed is not a simple removal of an alkanol molecule after a protonation on the alkoxy group. The mass spectrum of the m/z 166 ion for deuteron-charged methyl dihydrocinnamate showed two peaks of 1:5 intensity ratio at m/z 133 and 134 to confirm that the incipient proton is mobile. The proton initially attached to the carbonyl group migrates to the ring and randomizes before a subsequent transfer of one of the ring protons to the alkoxy group for the concomitant alcohol elimination. Moreover, protonated methyl dihydrocinnamate undergoes more than one H/D exchange. The spectra recorded from m/z 167 and 168 ions obtained for di- and tri-deuterio isotopologues showed peak pairs at m/z 134, 135 and 135, 136, at 1:2 and 1:1 intensity ratios, respectively, confirming the benzenium ion intermediate achieves complete randomization before the proton transfer. Additionally, protonated higher esters of alkyl dihydrocinnamates undergo a cleavage of the O-CH2 bond to form an ion/neutral complex, which, upon activation, dissociates generating a carbenium ion and dihydrocinnamic acid, or rearranges to generate protonated dihydrocinnamic acid and an alkene by a nonspecific proton transfer.
Copper-catalyzed highly efficient ester formation from carboxylic acids/esters and formates
Liu, Jun,Shao, Changdong,Zhang, Yanghui,Shi, Guangfa,Pan, Shulei
supporting information, p. 2637 - 2640 (2014/05/06)
A highly efficient copper-catalyzed protocol for the synthesis of esters has been developed from formates. This protocol is applicable to reactions with either esters or acids as the substrates, and shows broad substrate scopes and high yields. This journal is the Partner Organisations 2014.
Zinc-catalyzed amide cleavage and esterification of β- hydroxyethylamides
Kita, Yusuke,Nishii, Yuji,Higuchi, Takafumi,Mashima, Kazushi
, p. 5723 - 5726 (2012/08/07)
Snipping tool: Zn(OTf)2 is an efficient catalyst for selective cleavage of amides bearing a β-hydroxyethyl group on the nitrogen atom. The mechanism involves an N,O-acyl rearrangement and transesterification. This new catalytic system can be applied to sequence-specific peptide bond scission at the amine side of a serine residue. Tf=trifluoromethanesulfonyl. Copyright
Potassium phosphate / benzyltriethylammonium chloride as efficient catalytic system for transesterification
Cepanec, Ivica,Zivkovic, Andreja,Bartolincic, Anamarija,Mikuldas, Hrvoje,Litvic, Mladen,Merkas, Sonja
experimental part, p. 519 - 523 (2010/01/07)
Potassium phosphate (K3PO4) in the presence of benzyltriethylammonium chloride have been found to catalyses the transesterifications of a wide variety of aliphatic and aromatic esters with primary and secondary alcohols affording the corresponding esters in good-to-excellent yields.
Iridium-catalyzed oxidative esterification reaction of aliphatic aldehydes and olefinic alcohols with precoordination of the double bond of alcohols to iridium
Kiyooka, Syun-Ichi,Ueno, Mahuyu,Ishii, Eri
, p. 4639 - 4642 (2007/10/03)
A novel iridium-catalyzed oxidative esterification reaction of aliphatic aldehydes and olefinic alcohols in toluene was found under mild conditions of [IrCl(cod)]2 (5 mol %) in combination with K2CO 3 (10 mol %) at rt.
4-(Nitro)-diphenylammonium triflate(NDPAT) catalysed esterification of carboxylic acids with alcohols
Liu, Xuan-Gan,Hu, Wei-Xiao
, p. 564 - 565 (2007/10/03)
4-(Nitro)-diphenylammonium triflate(NDPAT) efficiently catalysed the esterification between equimolar amounts of carboxylic acids and alcohols in good yield under mild reaction conditions.
Improved procedure for the reductive acetylation of acyclic esters and a new synthesis of ethers
Kopecky, David J.,Rychnovsky, Scott D.
, p. 191 - 198 (2007/10/03)
An optimized protocol for the DIBALH reductive acetylation of acyclic esters and diesters is described. This reductive acetylation procedure allows a wide variety of esters to be converted into the corresponding α-acetoxy ethers in good to excellent yields. It was found that, under mild acidic conditions, many α-acetoxy ethers can be further reduced to the corresponding ethers. This net two-step ester deoxygenation is an attractive alternative to the classical Williamson synthesis for certain ethers.
