6137-73-1Relevant academic research and scientific papers
One-Pot Synthesis of α,β-Unsaturated Esters, Ketones, and Nitriles from Alcohols and Phosphonium Salts
Ding, Weijie,Hu, Juan,Jin, Huile,Yu, Xiaochun,Wang, Shun
, p. 107 - 118 (2017/09/28)
A general method for the synthesis of α,β-unsaturated esters, ketones, and nitriles is successfully achieved by a one-pot copper-catalyzed oxidation with O 2 in air as oxidant. The solvent mixture of acetonitrile and formamide (1:1) is optimized to ensure the oxidation of alcohols, deprotonation of phosphonium salt, and Wittig reaction occur efficiently in one pot. A broad range of substrates has been explored for this process, including three electron-withdrawing group (CO 2 Et, COPh, CN) functionalized phosphonium salts. They reacted not only with benzylic and heteroaromatic alcohols, but also with aliphatic alcohols, forming the corresponding α,β-unsaturated esters, ketones, and nitriles in moderate to excellent yields.
A Catalytic Peterson-like Synthesis of Alkenyl Nitriles
Lanari, Daniela,Alonzi, Matteo,Ferlin, Francesco,Santoro, Stefano,Vaccaro, Luigi
supporting information, p. 2680 - 2683 (2016/06/15)
A heterogeneous fluoride catalyst was found to enable the straightforward formation of alkenyl nitriles from the reaction of aldehydes and simple or substituted acetonitriles, in the presence of commercially available silazanes and in solvent-free conditions. The protocol afforded the products in good to excellent yields with selectivity values dependent on the nature of the substrates. It represents an alternative to classic approaches using stoichiometric strong bases, and the catalyst can be easily recovered and reused for consecutive cycles.
Cu-catalyzed debrominative cyanation of gem-dibromoolefins: A facile access to α,β-unsaturated nitriles
Ahuja, Brij Bhushan,Sudalai, Arumugam
, p. 5918 - 5923 (2015/06/02)
An efficient catalytic route for the synthesis of α,β-unsaturated nitriles from easily accessible gem-dibromoolefins has been developed. The method utilized inexpensive reagents such as Cu2O as a catalyst, l-proline as a ligand and NaCN as a cyanide source to afford α,β-unsaturated nitriles in high yields (62-86%). A deuterium exchange study has shown that one of the bromide atoms of gem-dibromoolefins exchanges with cyanide while the other with a deuterium atom.
Dual [Fe+Phosphine] catalysis: Application in catalytic wittig olefination
Rommel, Susanne,Belger, Christian,Begouin, Jeanne-Marie,Plietker, Bernd
, p. 1292 - 1301 (2015/04/27)
Iron hydride complexes of the general formula P2Fe(NO)CO)H are highly active catalysts for the hydrosilylation of aldehydes or ketones and phosphine oxides. Depending on the solvent, the in situ reduction of the phosphine oxide can be faster than the corresponding hydrosilylation of a carbonyl group. This unusual activity was used within the context of catalytic Wittig olefination. Picture perfect: Iron hydride complexes of the general formula P2Fe(NO)CO)H are highly active catalysts for the hydrosilylation of aldehydes or ketones and phosphine oxides. Depending on the solvent, the in situ reduction of the phosphine oxide can be faster than the corresponding hydrosilylation of a carbonyl group. This unusual activity is used within the context of catalytic Wittig olefination. EWG=Electron-withdrawing group.
Stereoselective olefination of N-sulfonyl imines with stabilized phosphonium ylides for the synthesis of electron-deficient alkenes
Fang, Fan,Li, Yuan,Tian, Shi-Kai
experimental part, p. 1084 - 1091 (2011/04/15)
An unprecedented protocol has been developed for thestereoselective synthesis of structurally diverse electron-deficient alkenes in moderate to excellent yields from readily accessible N-sulfonyl imines and stabilized phosphonium ylides. Significantly, the olefination reaction of N-sulfonylimines with nitrile-stabilized phosphonium ylides affords an array of α,β-unsaturated nitriles with high Z selectivity, and the reactions with ester-, amide-, and ketone-stabilized phosphonium ylides afford α,β-unsaturated esters, amides, and ketones with high E selectivity, respectively. Spectroscopic analysis of the reaction mixtures and trapping of the intermediates allow plausible mechanisms to be proposed. Initialimine/ylide addition leads to the formation of betaines that cyclize to form 1,2-azaphosphetanes that subsequently eliminate iminophosphoranes to yield alkenes. For the synthesis of electron-deficient 1,2-disubstituted alkenes, the presence of an electron-withdrawing group in the betaine allows rapid interconversion between its two diastereomers through proton transfer. The Z/E selectivity for alkene synthesis is determined by the different rates at which the two betaine diastereomers form the corresponding 1,2-azaphosphetane diastereomers. In contrast, the Z/E selectivity for the synthesis of electron-deficient trisubstituted alkenes originates from the diastereoselective addition of stabilized phosphonium ylides to N-sulfonyl imines.
A facile, one-pot synthesis of β-substituted (Z)-acrylonitriles utilizing an α-diaminoboryl carbanion
Tomioka, Takashi,Takahashi, Yusuke,Vaughan, Trey G.,Yanase, Takayoshi
supporting information; experimental part, p. 2171 - 2173 (2010/07/08)
A simple three-step single-pot procedure for Z-stereoselective synthesis of β-monosubstituted acrylonitriles has been established. The reaction involves olefination of aldehydes with an in situ generated α-diaminoboryl carbanion species. Various aromatic and aliphatic aldehydes were smoothly converted into the corresponding (Z)-olefin products (up to 96:4 ratio) in good yields (80-98%).
One-pot Wittig reactions in aqueous media: A rapid and environmentally benign synthesis of α,β-unsaturated carboxylic esters and nitriles
Wu, Jinlong,Yue, Congyong
, p. 2939 - 2947 (2007/10/03)
One-pot Wittig reactions of ethyl bromoacetate and bromoacetonitrile with aldehydes in the presence of PPh3 and LiOH in water were investigated. Most of the olefination reactions completed within 5-120 min in refluxing water containing 1.2 M LiCl to afford the olefin products in 71-97% yields with 100:0-55:45 ratios of E:Z isomers. Copyright Taylor & Francis Group, LLC.
The one-pot Wittig reaction: A facile synthesis of α,β- unsaturated esters and nitriles by using nanocrystalline magnesium oxide
Choudary, Boyapati M.,Mahendar, Koosam,Kantam, M. Lakshmi,Ranganath, Kalluri V. S.,Athar, Taimur
, p. 1977 - 1985 (2007/10/03)
Nanocrystalline magnesium oxide was found to be an effective heterogeneous, solid base catalyst for the one-pot Wittig reaction to afford α,β-unsaturated esters and nitriles in excellent yields with high E-stereoselectivity in the presence of triphenylphosphine under mild conditions.
Wittig reactions of stabilized phosphorus ylides with aldehydes in water
Wu, Jinlong,Zhang, Da,Wei, Shaoyong
, p. 1213 - 1222 (2007/10/03)
The Wittig reactions of three stabilized phosphorus ylides with aldehydes in water were investigated. Most of the olefination reactions completed within 5-60 min in refluxing water in the presence of 1.2 M LiCl to afford the olefin products in 65-98% yields. It was found that the Wittig reactions of stabilized phosphorus ylides with aldehydes in water were faster than those carried out in organic solvents. Copyright Taylor & Francis, Inc.
Highly (Z)-selective synthesis of β-monosubstituted α,β-unsaturated cyanides using the peterson reaction
Kojima, Satoshi,Fukuzaki, Tomohide,Yamakawa, Atsushi,Murai, Yutaka
, p. 3917 - 3920 (2007/10/03)
(Chemical Equation Presented) The Peterson reaction between (t-BuO)Ph 2SiCH2CN and various aldehydes furnishes the corresponding β-monosubstituted α,β-unsaturated cyanides with high Z selectivity (Z:E = 92:8 to >98:2).
