Expanded Ring NHC Silver Carboxylate Complexes as Efficient and Reusable Catalysts for the Carboxylative Cyclization of Unsubstituted Propargylic Derivatives
作者:Alejandro Cervantes‐Reyes、Tobias Saxl、Philipp M. Stein、Matthias Rudolph、Frank Rominger、Abdullah M. Asiri、A. Stephen K. Hashmi
DOI:10.1002/cssc.202002822
日期:2021.6.8
α-methylene cyclic carbonates. Derived from X-ray diffraction studies, the molecular geometry and the concept of buried volume were employed to describe the structural and steric features of these silver complexes. Their stability and efficiency as catalysts have been demonstrated by the synthesis of 29 carboxylation products (72–98 % yield) at low catalyst loadings (0.01–1.5 mol%). Characteristics are high
由庞大的 N-杂环卡宾 [ BP DPr, 1,3-双(2,6-二异丙基苯基)-1,3-diazonine-2-ylidene] 配体稳定,新的BP DPrAgO 2形式的羧酸银配合物CR (R=Me, Ph) 已在溶液和固态中合成并完全表征,并在具有挑战性的二氧化碳固定中用作唯一催化剂(碱、添加剂,在某些情况下,无溶剂)用于合成恶唑烷酮和α-亚甲基环状碳酸酯的未取代炔丙基衍生物。根据 X 射线衍射研究,分子几何形状和埋藏体积的概念被用来描述这些银配合物的结构和空间特征。它们作为催化剂的稳定性和效率已通过在低催化剂负载量(0.01-1.5 mol%)下合成 29 种羧化产物(72-98% 产率)得到证明。特点是周转数高(高达 9400)、催化剂可回收性(第 7 次循环后产率高达 96%,银络合物不分解),