Stereoselective Alkene Isomerization over One Position
作者:Casey R. Larsen、Douglas B. Grotjahn
DOI:10.1021/ja3036477
日期:2012.6.27
Although controlling both the position of the double bond and E:Z selectivity in alkene isomerization is difficult, 1 is a very efficient catalyst for selective mono-isomerization of a variety of multifunctional alkenes to afford >99.5% E-products. Many reactions are complete within 10 min at room temperature. Even sensitive enols and enamides susceptible to further reaction can be generated. Catalyst
Understanding Ligand‐Directed Heterogeneous Catalysis: When the Dynamically Changing Nature of the Ligand Layer Controls the Hydrogenation Selectivity
作者:Carsten Schröder、Marvin C. Schmidt、Philipp A. Haugg、Ann‐Katrin Baumann、Jan Smyczek、Swetlana Schauermann
DOI:10.1002/anie.202103960
日期:——
We present a mechanistic study on the formation and dynamic changes of a ligand-based heterogeneous Pd catalyst for chemoselective hydrogenation of α,β-unsaturated aldehyde acrolein. Deposition of allyl cyanide as a precursor of a ligand layer renders Pd highly active and close to 100 % selective toward propenol formation by promoting acrolein adsorption in a desired configuration via the C=O end.
Enolization of Aldehydes and Ketones: Structural Effects on Concerted Acid−Base Catalysis
作者:Anthony F. Hegarty、Joseph P. Dowling、Stephen J. Eustace、Michelle McGarraghy
DOI:10.1021/ja9729544
日期:1998.3.1
the product of the consecutive rate constants (kA·kB) and the concerted (third order) rate constants (kAB). This implies that the concerted pathway is important only when both the generalacid and the generalbase terms are significant; this will be useful in designing other systems which might show such concertedcatalysis. In the case of aldehydes, a slope of 0.97 was found for this plot, which compares
A new synthetic approach for 2-alkylchromanones utilizing Fe (III)-catalyzed reductive cross-coupling of olefins with chromones has been developed. The reaction conditions are mild, and various substituted alkenes are applicable to the process. Moreover, control experiments were conducted, and a plausible mechanism is proposed.
已经开发了一种利用 Fe (III) 催化烯烃与色酮的还原交叉偶联的 2-烷基色酮的新合成方法。反应条件温和,可适用多种取代烯烃。此外,还进行了控制实验,并提出了一个合理的机制。
Homogeneous catalysis. Catalytic production of simple enols
作者:Steven H. Bergens、B. Bosnich
DOI:10.1021/ja00003a032
日期:1991.1
for generating synthetically useful quantities of simpleenols from their corresponding allylic alcohols. A representative collection of simpleenols has been produced, and the physical properties and stabilities are recorded. Although these catalysts also ketonize (tautomerize) the enols to their corresponding aldehydes and ketones, the simpleenols are conveniently stable in solutions containing the