Sengoden Mani, Bhat Gulzar A, Rutledge Ryan J, Rashid Showkat, Dar Aijaz A, Darensbourg Donald J
Department of Chemistry, Texas A & M University, College Station, TX 77843.
Centre for Interdisciplinary Research and Innovations, University of Kashmir, Srinagar, Jammu and Kashmir 190006, India.
Proc Natl Acad Sci U S A. 2023 Nov 14;120(46):e2312907120. doi: 10.1073/pnas.2312907120. Epub 2023 Nov 3.
Metallosurfactants, defined here as hydrophobic metal-containing groups embedded in hydrophilic units when dispersed in water, emanate in the formation of metallomicelles. This approach continues to attract great interest for its ability to serve as micellar catalysts for various metal-mediated chemical transformations in water. Indeed, relevant to green chemistry, micellar catalysis plays a preeminent function as a replacement for organic solvents in a variety of chemical reactions. There are several methods for the interaction of metal complexes (catalysts or catalyst precursors) and surfactants for producing micellar aggregates. A very effective manner for achieving this involves the direct bonding of the metal center to the amphiphilic polymeric materials. Herein, we describe the synthesis of a metallosurfactant containing a palladium complex covalently incorporated into a CO-based triblock polycarbonate derived using a dicarboxylic acid chain-transfer agent. This amphiphilic polycarbonate was shown to self-assemble in water to provide uniform and spherical micelles, where the catalytic metal center is located in the hydrophobic portion of the micelle. The resulting metallosurfactant was demonstrated to effectively catalyze carbon-carbon coupling reactions at very low catalyst loadings.
金属表面活性剂在这里定义为当分散在水中时嵌入亲水性单元中的含疏水金属基团，在金属胶束的形成过程中产生。这种方法因其能够作为水相中各种金属介导的化学转化的胶束催化剂而持续吸引着极大的关注。事实上，与绿色化学相关，胶束催化在各种化学反应中作为有机溶剂的替代品发挥着卓越的作用。有几种使金属配合物（催化剂或催化剂前体）与表面活性剂相互作用以产生胶束聚集体的方法。实现这一目标的一种非常有效的方式是将金属中心直接键合到两亲性聚合物材料上。在此，我们描述了一种金属表面活性剂的合成，该金属表面活性剂包含一个共价结合到使用二羧酸链转移剂衍生的基于CO的三嵌段聚碳酸酯中的钯配合物。这种两亲性聚碳酸酯在水中自组装形成均匀的球形胶束，其中催化金属中心位于胶束的疏水部分。结果表明，所得金属表面活性剂在非常低的催化剂负载量下能有效催化碳 - 碳偶联反应。
