Organocatalytic diimide reduction of enamides in water
作者:Barrie J. Marsh、Emma L. Heath、David R. Carbery
DOI:10.1039/c0cc02272a
日期:——
Bridged flavinium organocatalysts have displayed efficacy in the diimide mediated reduction of enamides in aqueous conditions. This represents the first diimidereduction of an electron rich alkene and offers a clean alternative to the use of alkylating agents for N-alkylation.
Synergetic activation of CO<sub>2</sub> by the DBU-organocatalyst and amine substrates towards stable carbamate salts for synthesis of oxazolidinones
作者:Xiao-Chao Chen、Kai-Chun Zhao、Yin-Qing Yao、Yong Lu、Ye Liu
DOI:10.1039/d1cy01298c
日期:——
under mild conditions (80–100 °C, 12 h, 1.0 MPa CO2). Control experiments demonstrated that the formation of an ion-pair carbamate salt intermediate IS-B derived from the reaction of CO2, DBU (catalyst) and an amine (substrate) was the key step for this three-component reaction. The available DBU–amine–CO2 adduct intermediate (like IS-B-2) with fair stability will evolve into the thermodynamically stable
将CO 2转化为有价值的化学品的有效方法的开发引起了关于CO 2利用的挑战性问题的越来越多的关注。在此,DBU 有机超强碱催化CO 2、伯(脂肪族/芳香族)胺和 1,2-二氯乙烷(或其衍生物)制备恶唑烷酮的有效方法在温和条件下获得了 47-97% 的产率(80–100 °C, 12 h, 1.0 MPa CO 2 )。对照实验表明,由 CO 2反应生成的离子对氨基甲酸盐中间体IS-B、DBU(催化剂)和胺(底物)是这种三组分反应的关键步骤。可用的 DBU-胺-CO 2加合物中间体(如IS-B-2)在 1,2-二氯乙烷(或其衍生物)的攻击下,随着 DBU 的再生,将演变成热力学稳定的产物恶唑烷酮催化剂。或者,稳定性相对较差的 DBU-芳胺-CO 2加合物(如IS-B-1)的分解也可能导致 1,2-二氯乙烷(或其衍生物)与芳胺的竞争性取代反应。这项工作提供了对 DBU 催化剂和亲核胺底物协同 CO
Cooperative Catalysis of Ru(III)‐Porphyrin in CO
<sub>2</sub>
‐Involved Synthesis of Oxazolidinones
作者:Xiao‐Chao Chen、Yin‐Qing Yao、Kai‐Chun Zhao、Lei Liu、Yong Lu、Ye Liu
DOI:10.1002/asia.202100533
日期:2021.9
CO2, aliphatic amines and dichloroethane (or its derivative) for synthesis of oxazolidinones with yields of 71∼91%, CO2 was stoichiometrically activated by the involved aliphatic amine substrates to form a stable carbamate salt while 1,2-dichloroethane (or its derivative) was independently activated by the involved Ru(III)-porphyrin catalyst.
Najer et al., Bulletin de la Societe Chimique de France, 1957, p. 1069,1071
作者:Najer et al.
DOI:——
日期:——
Ethanol as a Hydrogenating Agent: Palladium-Catalyzed Stereoselective Hydrogenation of Ynamides To Give Enamides
作者:Alla Siva Reddy、K. C. Kumara Swamy
DOI:10.1002/anie.201702277
日期:2017.6.6
as a hydrogenatingagent for ynamides under palladium catalysis. This behavior is different from the normally expected reaction of ethanol addition to alkynes. The reaction shows stereoselectivity for E enamides, which is in contrast to reports using other hydrogenating sources. The method was also extended to ynamines. Alternatively, the use of ethanol and ammonium formate as the hydrogenating source