containing radical clocks, and experiments probing relative rates supports a hydrogen atom transfer pathway under thermal conditions that is enabled by a relatively weak cobalt–hydrogen bond of 54 kcal/mol. In contrast, data for the photocatalytic reactions support light-induced dissociation of a carbonyl ligand followed by a coordination-insertion sequence where the product is released by combination of
易于制备的配位饱和
钴(I)预催化剂(R,R)-(iPr D
UPhOS)Co(CO)2 H((R,R)-iPr D
UPhOS =(+)-1,2 -bis [(2 R,5 R)-2,5-
二异丙基膦酰基苯)。在加热到100°C时,观察到一系列烯烃的有效转化率,而在35°C的蓝光照射下,
钴催化剂的催化性能显着提高。这种改进的反应性使得末端,二和三取代的烯烃,
炔烃和羰基化合物的氢化成为可能。
氘标记研究,含自由基钟的烯烃加氢以及探索相对速率的实验相结合,支持了在热条件下通过54 kcal / mol相对较弱的
钴氢键实现的氢原子转移途径。相反,[R ,- [R )- (的iPr D
UPHOS)的Co(CO)2 H.这些结果证明催化与地球丰富的
金属的通用性为涉及开放与封闭壳中间体可通过能量源来切换路径。