7780-06-5Relevant articles and documents
Multiple-Functional Diphosphines: Synthesis, Characterization, and Application to Pd-Catalyzed Alkoxycarbonylation of Alkynes
Chen, Xiao-Chao,Guo, Lin,Liu, Lei,Liu, Ye,Lu, Yong,Yao, Yin-Qing,Zhao, Kai-Chun,Zhao, Xiao-Li
, p. 750 - 760 (2022/04/03)
A series of diphosphine ligands (L1-L5) containing bis-phosphino fragments and bis-amido groups as well as intensive electron-withdrawing F atoms were synthesized and fully characterized. The structures of the prepared complex of Pd-L5 demonstrate that as for L5, the incorporated two phosphino fragments participate in the chelation to the Pd center inversely along with two Cl-ligands to present a typical square-planar configuration, whereas the two amido groups simultaneously develop a hydrogen-bond interaction with Cl-ligands to facilitate the timely dissociation of Cl-ligands from the Pd center. It was found that L5 enabled the Pd complex to be more active in the alkoxycarbonylation of alkynes with MeOH for the synthesis of branched/linear α,β-unsaturated carboxylic esters with general yields of 60-89%. In L5, the incorporated diphosphino fragments, diamino groups, and F atoms conferred a catalytic effect to the Pd complex synergetic toward the reaction.
An ionic liquid catalyzed probase method for one-pot synthesis of α,β-unsaturated esters from esters and aldehydes under mild conditions
Wang, Gang,Xu, Yiming,Zhang, Suojiang,Li, Zengxi,Li, Chunshan
, p. 4838 - 4848 (2017/10/23)
A one-pot synthesis of α,β-unsaturated esters from unactivated esters and aldehydes using strong bases, such as sodium alkoxide and potassium tert-butoxide, was reported. However, the ionic liquid (IL) catalyzed probase method for producing α,β-unsaturated esters was not reported until now. In this work, a series of ILs with fluoride anions were firstly prepared and used as catalysts in combination with the probase N,O-bis(trimethylsilyl) acetamide (BSA) for the α,β-unsaturated esters synthesis. This process could also be promoted through the introduction of another IL with Lewis acid sites. The yield and selectivity of the product could reach up to 84.2% and 95.0%, respectively, when [Bmim]F was used in combination with [Bmim]Cl/AlCl3 (the molar fraction of AlCl3 is 0.67). The mechanism investigation through GC-MS indicates that BSA would convert into onium amide, which acted as a strong base for α-H abstraction, with the catalysis of [Bmim]F. Meanwhile, [Bmim]Cl/AlCl3 played an important role in the condensation step between enolates and aldehydes. On the basis of mechanism insights, kinetic and thermodynamic studies were also carried out for a better understanding of this new route.
Appel reaction of carboxylic acids with tribromoisocyanuric acid/triphenylphosphine: A mild and acid-free preparation of esters and amides
Da Cunha Sindra, Haryadylla,De Mattos, Marcio C.S.
, p. 1129 - 1136 (2016/07/06)
A facile and efficient method for esterification and amidation of carboxylic acids under neutral conditions has been developed. Esters and amides can be prepared by reacting a carboxylic acid (1 mmol) with tribromoisocyanuric acid (0.37 mmol) and triphenylphosphine (1 mmol) in dichloromethane at room temperature, followed by addition of an alcohol or an amine, respectively.
