Remarkable contrast between chemospecificities in acid-mediated arylation of δ- and γ-ketocarboxylic acids was revealed: in the presence of P2O5–MsOH, TfOH, PPA, and MsOH, arylation of δ-ketocarboxylic acid 1A with arenes takes place at the carboxycarbonyl carbon, while that of γ-ketocarboxylic acid 1B takes place at the ketone carbonyl carbon, specifically.
Cycloalkyl alkanoic acids as integrin receptor antagonists derivatives
申请人:——
公开号:US20040092538A1
公开(公告)日:2004-05-13
The present invention relates to a class of compounds represented by the Formula I
1
or a pharmaceutically acceptable salt thereof, pharmaceutical compositions comprising compounds of the Formula I, and methods of selectively inhibiting or antagonizing the &agr;
v
&bgr;
3
and/or &agr;
v
&bgr;
5
integrin.
本发明涉及一类由公式I代表的化合物
1
或其药用可接受的盐,包含公式I化合物的药物组合物,以及选择性地抑制或拮抗α
v
β
3
和/或α
v
β
5
整合素的方法。
Pd(OAc)<sub>2</sub>/DABCO as a Highly Active Catalytic System for the Heck Reaction
作者:Jin-Heng Li、De-Ping Wang、Ye-Xiang Xie
DOI:10.1055/s-2005-869980
日期:——
The combination of Pd(OAc)2 and DABCO (triethylenediamine) was observed as an efficient catalytic system for the Heck cross-coupling reaction. In the presence of Pd(OAc)2 and DABCO, a number of ArX (X = I, Br, and Cl) were coupled with olefins efficiently and selectively to afford the corresponding unsymmetric internal olefins in good to excellent yields. Furthermore, the Pd(OAc)2/DABCO-catalyzed Heck cross-coupling reaction provided high TONs up to 1,000,000.
Ligand- and Base-Free Pd(II)-Catalyzed Controlled Switching between Oxidative Heck and Conjugate Addition Reactions
作者:Sarah E. Walker、Julian Boehnke、Pauline E. Glen、Steven Levey、Lisa Patrick、James A. Jordan-Hore、Ai-Lan Lee
DOI:10.1021/ol400539h
日期:2013.4.19
solvent allows controlled and efficient switching between oxidative Heck and conjugateadditionreactions on cyclic Michael acceptor substrates, catalyzed by a cationic Pd(II) catalyst system. Both reactions are ligand- and base-free and tolerant of air and moisture, and the controlled switching sheds light on some of the factors which favor one reaction over the other.
Selective arylation at the vinylic site of cyclic olefins
作者:Xiaojin Wu、Jianrong (Steve) Zhou
DOI:10.1039/c3cc41722k
日期:——
Cyclicolefins usually give Heck products having an aryl ring residing at the allylic or homoallylic position. We describe herein a new method that allows arylation at the vinylic position of various cyclicolefins.