<i>Ex Situ</i> Generation of Stoichiometric and Substoichiometric <sup>12</sup>CO and <sup>13</sup>CO and Its Efficient Incorporation in Palladium Catalyzed Aminocarbonylations
作者:Philippe Hermange、Anders T. Lindhardt、Rolf H. Taaning、Klaus Bjerglund、Daniel Lupp、Troels Skrydstrup
DOI:10.1021/ja200818w
日期:2011.4.20
CO-precursor led to the development of a new solid, stable, and easy to handle source of CO for chemical transformations. The synthesis of this CO-precursor also provided an entry point for the late installment of an isotopically carbon-labeled acid chloride for the subsequent release of gaseous [(13)C]CO. In combination with studies aimed toward application of CO as the limiting reagent, this method provided
使用简单的密封两室系统实现了异位生成一氧化碳 (CO) 及其在钯催化的羰基化反应中的有效结合的新技术。CO 的异位生成是通过钯催化的叔酰氯脱羰使用源自 Pd(dba)(2) 和 P(tBu)(3) 的催化剂产生的。使用新戊酰氯作为 CO 前体的初步研究为仅使用 1.5 当量的 CO 对 2-吡啶基甲苯磺酸酯衍生物进行氨基羰基化提供了另一种方法。 酰氯 CO 前体的进一步设计导致开发了一种新的固体、稳定、并且易于处理用于化学转化的 CO 源。这种 CO 前体的合成也为后期安装同位素碳标记的酰氯以随后释放气态 [(13)C]CO 提供了切入点。结合旨在应用 CO 作为限制剂的研究,该方法提供了高效的钯催化氨基羰基化,CO 结合率高达 96%。异位生成的 CO 和双室系统在几种药物化合物的合成中进行了测试,所有这些化合物都被标记为 [(13)C] 羰基对应物,基于限制 CO 的产率从良好到极好。
Zirconium Oxide‐Catalyzed Direct Amidation of Unactivated Esters under Continuous‐Flow Conditions
A sustainable and environmentallybenign direct amidation reaction of unactivated esters with amines has been developed in a continuous-flow system. A commercially available amorphous zirconium oxide was found to be an efficientcatalyst for this reaction. While the typical amidation of esters with amines requires a stoichiometric amount of a promoter or metal activator, the present continuous-flow
The one-pot formation of amides by oxidative coupling of alcohols and amines via intermediate formation of methyl ester using supported gold and base as catalysts was studied using the Hammett methodology. Determining the relative reactivity of four different para-substituted benzyl alcohol derivatives showed that the first step of the reaction generates a partial positive charge in the benzylic position
[EN] SYSTEM PROVIDING CONTROLLED DELIVERY OF GASEOUS CO FOR CARBONYLATION REACTIONS<br/>[FR] SYSTÈME PERMETTANT LA LIBÉRATION CONTRÔLÉE DE CO GAZEUX POUR RÉACTIONS DE CARBONYLATION
申请人:UNIV AARHUS
公开号:WO2012079583A1
公开(公告)日:2012-06-21
A carbonylation system comprising at least one carbon monoxide producing chamber and at least one carbon monoxide consuming chamber forming an interconnected multi-chamber system, said interconnection allowing carbon monoxide to pass from the at least one carbon monoxide producing chamber to the at least one carbon monoxide consuming chamber, said at least one carbon monoxide producing chamber containing a reaction mixture comprising a carbon monoxide precursor and a catalyst, said at least one carbon monoxide consuming chamber being suitable for carbonylation reactions, said interconnected multi- chamber system being sealable from the surrounding atmosphere during carbonylation.
<sup>14</sup>Carbon monoxide made simple - novel approach to the generation, utilization, and scrubbing of<sup>14</sup>carbon monoxide
作者:Anders T. Lindhardt、Roger Simonssen、Rolf H. Taaning、Thomas M. Gøgsig、Göran N. Nilsson、Gunnar Stenhagen、Charles S. Elmore、Troels Skrydstrup
DOI:10.1002/jlcr.2962
日期:2012.9
A new method is reported for the efficient generation of 14CO that can be applied in transition metal-catalyzed carbonylation reactions. 14CO is produced by palladium-catalyzed decarbonylation of the stable acid chloride, 14COgen. When combined in a two-chamber system, the produced 14CO is incorporated into the target molecule with high efficiency. As the carbonylation chemistry is performed under mild conditions, this allows the 14C isotope to enter the synthesis into an advanced stage intermediate. The presented work includes two aminocarbonylations, one amidocarbonylation, and one carbonylative Suzuki–Miyaura coupling, all installing the 14C isotope in the final step of the synthesis. Finally, the identification of a highly efficient scrubber for the safe trapping and removal of any leftover 14CO is also disclosed.