Synthesis of a Simplified Version of Stable Bulky and Rigid Cyclic (Alkyl)(amino)carbenes, and Catalytic Activity of the Ensuing Gold(I) Complex in the Three-Component Preparation of 1,2-Dihydroquinoline Derivatives

Abstract

A 95/5 mixture of cis and trans 2,4-dimethyl-3-cyclohexenecarboxaldehyde (trivertal), a common fragrance and flavor material produced in bulk quantities, serves as the precursor for the synthesis of a stable spirocyclic (alkyl)(amino)carbene, in which the 2-methyl-substituted cyclohexenyl group provides steric protection to an ensuing metal. The efficiency of this carbene as ligand for transition metal based catalysts is first illustrated by the gold(I) catalyzed hydroamination of internal alkynes with secondary dialkyl amines, a process with little precedent. The feasibility of this reaction allows for significantly enlarging the scope of the one-pot three-component synthesis of 1,2-dihydroquinoline derivatives, and related nitrogen-containing heterocycles. Indeed, two different alkynes were used, which include an internal alkyne for the first step.

Cyclic(alkyl)(amino)carbenes and the Research Prospect in Olefin Metathesis Reaction

“…若用 CAACs 替换这些催化剂中的环二氨基卡宾或膦配体, 则可以得到一系列新型 CAACs 钌卡宾催化剂. 芳基化 [8] 以及非端基炔烃的氢胺化 [44] 等诸多反应中, 催 化效果甚至优于带有环二氨基卡宾配体类型的催化剂.…”

Stabile cyclische Carbene und verwandte Spezies jenseits der Diaminocarbene

“…[70] Sowohl Homo-als auch Kreuzkupplungen können stattfinden, und die einzigste ernsthafte Beschrän-kung besteht in der Verwendung von terminalen Alkinen im zweiten Schritt. Damit gelingt es leicht, drei unterschiedliche Substituenten R 1 , R 2 und R 3 in das Dihydrochinolingerüst einzuführen.…”

Diverse Chemical Applications of N-Heterocyclic Carbenes

“…Bertrand reported an easily synthesized, sterically hindered NHC that allows low-coordinate gold(I) to be prepared. 10 This species was shown to be an efficient catalyst for the addition of secondary dialkylamines to internal alkynes, a process that has little precedent. As analogues of phosphines, NHC-derived catalysts are expected to have similar chemistry.…”