2588-79-6Relevant articles and documents
Recycling of homogeneous catalysts in reactive ionic liquid-solvent-free aminofunctionalizations of alkenes
Fa?bach, Thiemo A.,Kirchmann, Robin,Behr, Arno,Vorholt, Andreas J.
supporting information, p. 5243 - 5249 (2017/11/09)
The catalyst in homogeneously catalyzed aminofunctionalizations is often difficult to recycle, making these reactions expensive on an industrial scale. The use of dimethylammonium dimethylcarbamate (dimcarb) as a reactive ionic liquid provides an elegant solution to this challenge, as it is a substrate and polar phase at the same time. In this work, homogeneously transition-metal catalyzed reactions-specifically hydroamination, telomerization and hydroaminomethylation-are carried out in neat substrates without additional solvents. The ionic character of dimcarb enables the immobilization of the active catalysts in the reactive ionic liquid, using sulfonated ligands. Investigations regarding the hydroamination of 1,3-dienes led to a total turnover number (TTON) of more than 8700 with β-farnesene in 12 repetitive recycling experiments. The telomerization of 1,3-butadiene was carried out over 30 consecutive runs without any loss of activity, resulting in a TTON of more than 90 000.
Base Catalysed Rearrangements involving Ylide Intermediates. Part 16. The Preparation and Thermal Rearrangement of Allylammonioamidates
Chantrapromma, Kan,Ollis, W. David,Sutherland, Ian O.
, p. 1029 - 1039 (2007/10/02)
The ammonioamidates (7) and (11) undergo rearrangement (R3=CH2Ph) and competing and rearrangements (R3=allyl).The rates of the and rearrangements of the cinnamyl ammonioamidates (11a), (11b), (11d), and (11g) show similar dependence on the nature of the substituent X.The rate of the rearrangement of the reaction products (14b), (14d), and (14g) is relatively insensitive to substituent effects, suggesting that the rates of ammonioamidate rearrangements are largely controlled by conjugation between the group X and the N(-)CO system.The and rearrangements of the cinnamylammonioamidate (11d) show moderate and similar dependence upon solvent polarity suggesting that the transition state for both reactions has considerable dipolar character.The apparent intramolecularity of the and rearrangements of the cinnamylammonioamidate (11e) as estimated by isotopic mixing methods is decreased by isotopic scrambling in the ylide due to radical recombination to give ylide (11l) in addition to products (13l) and (14l).If allowance is made for this effect the rearrangement appears to be largely, or even entirely, intramolecular and the rearrangement shows intermolecularity comparable with that found for the rearrangements of analogous ammonium ylides under similar reaction conditions.
INVESTIGATIONS IN THE FIELD OF AMINES AND AMMONIUM COMPOUNDS. CLV. STEVENS REARRANGEMENT WITH THE PARTICIPATION OF A METHYL-SUBSTITUTED ALKOXYCARBONYLMETHYL GROUP
Kocharyan, S. T.,Grigoryan, V. V.,Voskanyan, V. S.,Panosyan, G. A.,Babayan, A. T.
, p. 1619 - 1622 (2007/10/02)
Under the influence of sodium methoxide in ether ammonium salts containing a methyl-substituted alkoxycarbonylmethyl group together with a group of the allylic type undergo a Stevens rearrangement with the formation of the esters of substituted 2-dimethylamino-4-pentenoic acids.The susceptibility to thermal isomerisation in the products from rearrangement of salts containing a γ-phenylallyl or γ,γ-dimethylallyl group as migrating group increases greatly if there is a methyl or allyl substituent in the methoxycarbonylmethyl group.
