Catalytic Cleavage of Carbon Unreactive Bonds by the Coordination of a Directing Group

(1)探索了N-2-吡啶基烷基胺中与氮原子相邻的sp^3 C-H键断裂的催化反应。使用Ru_3(CO)_12作为催化剂导致sp^3C-H键跨过烯键加成得到偶联产物。多种烯烃，包括末端烯烃、内部烯烃和环状烯烃，可用于偶联反应。胺氮上吡啶、嘧啶和恶唑啉环等导向基团的存在对于反应成功至关重要。(2)吡啶酯与HCOONH_4在Ru_3(CO)_12存在下发生脱羰还原反应生成烃。使用有机硼化合物作为偶联伙伴导致交叉偶联反应生成酮，并且没有发生脱羰基反应。氢硅烷也可以用作还原剂来代替HCOONH_4。多种官能团都适合这两种反应。这两种催化反应的关键步骤是酯中酰基碳-氧键的定向基团促进断裂，从而生成酰基过渡金属烷氧基配合物。(3)在钌或铑配合物的催化下，实现了N-苯基吡唑苯环上C-H键的直接羰基化。 N-苯基吡唑与一氧化碳和乙烯在Ru_3(CO)_12或Rh_4(CO)_12存在下反应，导致苯环中邻位C-H键的位点选择性羰基化，得到相应的乙基酮。苯环上可以容忍多种官能团。根据吡唑共轭酸的 pKa 值，N-苯基吡唑的反应活性高于预期。该反应溶剂的选择很重要，N,N-二甲基乙酰胺(DMA)得到了最好的结果。(4)在Rh_4(CO)_12存在下，烯烃与吡啶甲醇和CO反应，在相对温和的反应条件下发生了加氢酯化反应。使用苯甲醇代替吡啶甲醇没有发生反应。较少的

(1)Catalytic reactions which involve the cleavage of an sp^3 C-H bond adjacent to a nitrogen atom in N-2-pyridynyl alkylamines are explored. The use of Ru_3(CO)_<12> as the catalyst results in the addition of the sp^3C-H bond across alkene bond to give the coupling products. A variety of alkenes, including terminal, internal, and cyclic alkenes, can be used for the coupling reaction. The presence of directing groups, such as pyridine, pyrimidine, and an oxazoline ring, on the nitrogen of the amine is critical for a successful reaction.(2)The reaction of pyrydinyl esters with HCOONH_4 in the presence of Ru_3(CO)_<12> resulted in decarbonylative reduction to give hydrocarbons. The use of organoboron compounds as a coupling partner resulted in cross-coupling reaction to give ketones, and no decarbonylation took place. A hydrosilane can also be used as a reducing reagent in place of HCOONH_4. A wide variety of functional groups are compatible for both reactions. The key step for both catal … More ytic reactions is the directing group-promoted cleavage of an acyl carbon-oxygen bond in esters, leading to the generation of acyl transition metal alkoxo complexes.(3)The direct carbonylation of C-H bonds in the benzene ring of N-phenylpyrazoles via catalysis by ruthenium or rhodium complexes was achieved. The reaction of N-phenylpyrazoles with carbon monoxide and ethylene in the presence of Ru_3(CO)_<12> or Rh_4(CO)_<12> resulted in the siteselective carbonylation of the ortho C-H bonds in the benzene ring to give the corresponding ethylketones. A variety of functional groups on the benzene ring can be tolerated. N-Phenylpyrazoles have higher reactivities than would be expected, based on the pKa values of the conjugate acid of pyrazole. The choice of solvent for this reaction is significant, and N, N-dimethylacetamide (DMA) gives the best result.(4)The reaction of alkenes with pyridinemethanol and CO in the presence of Rh_4(CO)_<12> resulted in hydroesterification under relatively mild reaction conditions. The use of benzyl alcohol in place of pyridinemethanol gave no reaction. Less