116576-40-0Relevant articles and documents
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.
Synthesis of 1-Fluoro-2-Phenylvinyl Piperidino Ketones
Shen, Yanchang,Zhou, Yuefen
, p. 3081 - 3084 (2007/10/02)
A new palladium-catalysed synthesis of 1-fluoro-2-phenylvinyl piperidino ketones is described.
A new one-pot synthesis of α,β-unsaturated amides
Zheng,Wang,Shen
, p. 1611 - 1617 (2007/10/02)
A new one-pot synthesis of α,β-unsaturated amides with high stereoselectivity by the reaction of aldehydes with bromoacetamides promoted by tri-n-butylphosphine and zinc is described.
Palladium-catalyzed conversion of aldehydes to (2E)-, (2E,4E)-unsaturated amides in the presence of tri-n-butyl-arsine or phosphine
Shen,Zhou
, p. 657 - 664 (2007/10/02)
Palladium-catalyzed conversion of aldehydes to (2E)-, (2E,4E)-unsaturated amides in the presence of tri-n-butyl-arsine or -phosphine is described.
Lactam and Amide Acetals: Part XVII - Reactions of 1,1-Dimethoxy-1-(N-piperidinyl)ethane and 2-Ethoxy-1-methylindole with Electrophiles
Jotwani, Padma,Singh, Jujhar,Anand, Nitya
, p. 1039 - 1041 (2007/10/02)
Reactions of araldehydes with 1,1-dimethoxy-1-(N-piperidinyl)ethane (1) yield 3-aryl-1-(N-piperidinyl)-2-propen-1-ones (3-10), while 2-ethoxy-1-methylindole (2) reacts with araldehydes to afford aryldi-(2-ethoxy-1-methylindole-3-yl)methanes (11-16).Reaction of 2 with phenyl isocyanate and phenyl isothiocyanate gives 2-ethoxy-1-methyl-3-phenylcarbamoyl and thiocarbamoylindoles (17 and 18) respectively.