In the work reported herein, the concise and enantioselective total synthesis of the Schizozygine alkaloid (−)-strempeliopine was developed. This synthetic strategy featured the palladium-catalyzed decarboxylative asymmetric allylic alkylation of N-benzoyl lactam to set up the absolute configuration at the C20 position, a highly diastereoselective one-pot Bischler–Napieralski/lactamization and iminium
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+