Ruthenium-Catalyzed Direct Carbonylation at C-H Bonds

科学研究资助(B)的目的是在直接羰基化反应研究中获得的知识的基础上，发展C-H键直接羰基化和开发新的催化反应。结果，我们发现了以下结果。我们已经报道了钌催化咪唑与CO和烯烃反应中C-H键α到sp^2氮的羰基化反应。我们发现其他五元n -杂芳香化合物，如恶唑、噻唑和吡唑也可以用于羰基化反应。底物的反应活性与底物共轭酸的pKa相对应。底物的pKa越高，反应活性越高。我们已经报道了钌催化吡啶苯与CO和烯烃反应中C-H键邻位羰基化反应，其中吡啶环作为导向基团。发现恶唑啉环也可以作为羰基化反应的导向基团。在某些底物中，即使在1atm的CO浓度下，反应也能进行。目前我们发现的所有羰基化反应都是sp^2碳氢键上的羰基化。发现在铑配合物的催化下，烷基胺中sp^3 C-H键α与氮原子的羰基化反应。

The purpose of Grant-in-Aid for Scientific Research (B) was the development of direct carbonylation at C-H bonds and the development of new catalytic reactions based on the knowledge obtained from the research on the direct carbonylation reactions. As a result, we found the following results.We have already reported the ruthenium-catalyzed carbonylation at C-H bonds α to the sp^2 nitrogen in the reaction of imidazoles with CO and olefins. We found that other five-membered N-heteroaromatic compounds, such as oxazoles, thiazoles, and pyrazoles can also be used for the carbonylation reaction. The reactivity of the substrates corresponds to the pKa of the conjugate acid of the substrates. The higher pKa of the substrates, the higher is the reactivity.We have already reported the ruthenium-catalyzed carbonylation at C-H bond ortho position in the reaction of pyridylbenzenes with CO and olefins, in which the pyridine ring acts as a directing group. It is found that an oxazoline ring can also act as a directing group for the carbonylation reaction. The reaction can proceed even at 1 atm of CO in some substrates.All of carbonylation reactions we found thus far are carbonylation at sp^2 C-H bonds. It is found that sp^3 C-H bonds α to the nitrogen atom in alkylamines can be carbonylated in the presence of a rhodium complex as the catalyst.