An in situ generated dinuclear palladium hydride complex bearing cis,trans,cis-1,2,3,4-tetrakis(diphenylphosphanyl)cyclobutane catalyzed the hydromethoxycarbonylation of terminal alkynes, giving the corresponding branched α,β-unsaturated ester (A) with high regioselectivity.
Catalytic asymmetric synthesis of 5-membered alicyclic α-quaternary β-amino acids <i>via</i> [3 + 2]-photocycloaddition of α-substituted acrylates
作者:Yuto Kimura、Daisuke Uraguchi、Takashi Ooi
DOI:10.1039/d1ob00126d
日期:——
stereoselective [3 + 2]-cycloaddition of cyclopropylurea with α-substituted acrylates. This protocol provides straightforward access to a variety of stereochemically defined 5-membered alicyclic α-quaternary β-amino acids, useful building blocks of β-peptides and peptidomimetics.
Brønsted acidic ionic liquid as an efficient and recyclable promoter for hydroesterification of olefins catalyzed by a triphenylphosphine–palladium complex
作者:Jing Yang、Hancheng Zhou、Xinning Lu、Youzhu Yuan
DOI:10.1016/j.catcom.2010.05.025
日期:2010.9
Several Bronsted acidic ionic liquids (BAILs) with different acidic scales were synthesized and employed as acid promoters for the hydroesterification of olefins catalyzed by a triphenylphosphine-palladium complex. The results showed that catalysts with BAIL promoters resulted in moderate to high conversions to the ester product with excellent selectivity, depending on the acidity of BAIL used. The reaction conversion reached a plateau when the catalyst was promoted using BAIL with a Hammett acidity function less than or equal to -0.11. This catalyst system could be reused several times for the hydroesterification of 1-hexene without a considerable decrease in the catalytic performance. (C) 2010 Elsevier B.V. All rights reserved.
HO W.; TUTWILER G. F.; COTTRELL S. C.; MORGANS D. J.; TARHAN O.; MOHRBACH+, J. MED. CHEM., 29,(1986) N 11, 2184-2190
作者:HO W.、 TUTWILER G. F.、 COTTRELL S. C.、 MORGANS D. J.、 TARHAN O.、 MOHRBACH+