55305-86-7Relevant academic research and scientific papers
P[N(i-Bu)CH2CH2]3N: Nonionic Lewis base for promoting the room-temperature synthesis of α,β-unsaturated esters, fluorides, ketones, and nitriles using Wadsworth - Emmons phosphonates
Chintareddy, Venkat Reddy,Ellern, Arkady,Verkade, John G.
supporting information; experimental part, p. 7166 - 7174 (2010/12/25)
The bicyclic triaminophosphine P(RNCH2CH2) 3N (R = i-Bu, 1c) serves as an effective promoter for the room-temperature stereoselective synthesis of α,β-unsaturated esters, fluorides, and nitriles from a wide array of aromatic, aliphatic, heterocyclic, and cyclic aldehydes and ketones, using a range of Wadsworth-Emmons (WE) phosphonates. Among the analogues of 1c [R = Me (1a), i-Pr (1b), Bn (1d)], 1a and 1b performed well, although longer reaction times were involved, and 1d led to poorer yields than 1c. Functionalities such as cyano, chloro, bromo, methoxy, amino, ester, and nitro were well tolerated. We were able to isolate and characterize (by X-ray means; see above) the reactive WE intermediate species formed from 2b and 1c.
Scope and limitations of the Julia-Kocienski reaction with fluorinated sulfonylesters
Calata, Charlène,Catel, Jean-Marie,Pfund, Emmanuel,Lequeux, Thierry
experimental part, p. 3967 - 3973 (2009/09/25)
The study of the Julia-Kocienski reaction between fluorinated arylsulfone and ketones is described. The corresponding fluoroalkenes were isolated in moderate to good yields from β- and δ-substituted cyclic ketones. From acyclic ketones and α-substituted c
Phosphonium supported triphenylphosphine reagent: an improved access to α-fluoro-α,β-unsaturated esters
Zoute, Ludivine,Lacombe, Céline,Quirion, Jean-Charles,Charette, André B.,Jubault, Philippe
, p. 7931 - 7933 (2007/10/03)
α-Fluoro-α,β-unsaturated esters 2 were efficiently synthetized via diethylzinc-promoted Wittig reaction using a phosphonium-supported triphenylphosphine SCG-PPh3 1, which possesses similar reactivity as its parent analog triphenylphosphine. The
Efficient synthesis of fluoroalkenes via diethylzinc-promoted wittig reaction
Zoute, Ludivine,Dutheuil, Guillaume,Quirion, Jean-Charles,Jubault, Philippe,Pannecoucke, Xavier
, p. 3409 - 3418 (2008/02/11)
The synthesis of α-fluoroacrylates and α-bromo-α- fluoroalkenes was achieved in very good yields using aldehydes and ketones, triphenylphosphine, diethylzinc as promoter, and ethyl dibromofluoroacetate or dibromofluoromethane, respectively. A change in th
Z-selective or stereospecific alkenylation reaction: A novel synthetic method for α-fluoro-α,β-unsaturated esters
Yoshimatsu, Mitsuhiro,Murase, Yoshinori,Itoh, Akinori,Tanabe, Genzoh,Muraoka, Osamu
, p. 998 - 999 (2007/10/03)
The Z-selective formation of α-fluoro-α,β-unsaturated esters was achieved using the deselenenic acid of the syn-and/or anti-3-aryl-2-fluoro-3-hydroxy-2-organoselanylacetates 3 and 4 with trifluoromethanesulfonic acid. In contrast, the 3-alkyl-substituted propanoates 3f and 4b stereospecifically underwent alkenylation to give the (E)- or (Z)-α-fluoro-α,β-unstaurated esters 5f. We were also successful in the one-pot alkenylation reactions. Copyright
Fluoro-olefins as peptidomimetic inhibitors of dipeptidyl peptidases
Van Der Veken, Pieter,Senten, Kristel,Kertèsz, István,De Meester, Ingrid,Lambeir, Anne-Marie,Maes, Marie-Berthe,Scharpé, Simon,Haemers, Achiel,Augustyns, Koen
, p. 1768 - 1780 (2007/10/03)
The feasibility of the fluoro-olefin function as a peptidomimetic group in inhibitors for dipeptidyl peptidase IV and II (DPP IV and DPP II) is investigated by evaluation of N-substituted Gly-Ψ[CF=C]pyrrolidines, Gly-Ψ[CF=C]piperidines, and Gly-Ψ[CF=C](2-cyano)pyrrolidines. Of this later class, the (Z)- and (E)-fluoro-olefin analogues were prepared and chemical stability in comparison with the parent amide was checked. Most of these compounds exhibited a strong binding preference toward DPP II with IC 50 values in the low micromolar range, while only low DPP IV inhibitory potential is seen.
The reaction of α-diazo-β-hydroxy esters with boron trifluoride etherate: Generation and rearrangement of destabilized vinyl cations. A detailed experimental and theoretical study
Pellicciari, Roberto,Natalini, Benedetto,Sadeghpour, Bahman M.,Marinozzi, Maura,Snyder, James P.,Williamson, Bobby L.,Kuethe, Jeffrey T.,Padwa, Albert
, p. 1 - 12 (2007/10/03)
Cyclic ethyl 2-diazo-3-hydroxy carboxylates were prepared by treating ethyl diazoacetate with LDA followed by reaction with a series of cyclic ketones. Further treatment of these α-diazo-β-hydroxy esters with boron trifluoride etherate in various solvents affords an unusual array of products. Product types and ratios were found to be strongly dependent on ring size and the solvent used. The reaction proceeds by Lewis acid complexation of the alcohol functionality of the diazo hydroxy ester with BF3 etherate followed by neighboring-group participation of the diazo moiety to generate a cycloalkylidene diazonium salt. Loss of nitrogen produces a highly reactive, destabilized, linear vinyl cation. Ring expansion via a 1,2-methylene shift leads to the formation of a more stable, bent cycloalkenyl vinyl cation. A subsequent 1,2-methylene shift results in ring contraction ultimately leading to a stable allylic cation. This cation is either trapped by the solvent or else undergoes cyclization with the adjacent ester group to give a lactone. Computational studies at the 6-31G* level were performed to determine the geometry of the optimized vinyl cations. Relative energies suggest a moderate energy gain for isomerization of the initial vinyl cation V1 to the rearranged vinyl cation V2 followed by a large stabilization in energy for subsequent conversion to the allyl cation A1. Compared with isolated product distributions, the energy profiles suggest kinetically-controlled V1 → V2 → A1 migrations. Finally, the calculations suggest that in diethyl ether the carbocations may be coordinated to a molecule of solvent resulting in "protected" cationic intermediates with nonlinear geometries.
The Reaction of α-Diazo-β-hydroxy Esters with Boron Trifluoride
Pellicciari, Roberto,Natalini, Benedetto,Sadeghpour, Bahman M.,Rosato, Giovanni C.,Ursini, Antonella
, p. 1798 - 1800 (2007/10/02)
Exposure of a cyclic α-diazo-β-hydroxy ester to different concentrations of boron trifluoride in various solvents affords an interesting variety of products.
