Carbonylative C-H Activations

In summary, we have summarized representative examples of transition-metal-catalyzed carbonylative domino reactions. In the area of carbonylations, palladium, rhodium, and cobalt are still the main actors. The abihty of palladium catalysts in carbonylative cross-coupling, rhodium catalysts in carbonylative C-H activation, and cobalt catalyst in carbonylative reactions with unsaturated bonds is impressive. 

The first report on a palladium-catalyzed carbonylative C-H activation was published in 1986 by Kobayashi and Tanaka [1]. They reported that the carbonylation of organic halides with activated methylene compounds in the presence of NEta under 20 bar of CO produces various ketones in good yields (Scheme 6.1). Aryl iodides, bromobenzene and one example of a vinyl bromide were used as starting materials. But relatively high pressure and high pressure are needed, and tri-ethylamine was used both as a base and solvent. 

Above we mentioned the palladium-catalyzed carbonylative coupling of organohalides with C-H nucleophiles. Compared with their version of carbonylative coupling with organometaUic reagents, the pre-activation of C-H bonds was not needed. The other pathway in carbonylative C-H activation is the reaction between two nucleophiles in the presence of an additional oxidant sometimes these types of reactions are also called oxidative carbonylations. Only the reaction between Ar-H and nucleophiles will be discussed in the following the other oxidative carbonylation reactions will be summarized in Chap. 8. 

In addition to palladium catalysts, ruthenium catalysts were applied in carbonylative C-H activation reactions as well. Moore and colleagues described the first ruthenium-catalyzed carbonylative C-H activation reaction in 1992 [52], Orf/io-acylation of pyridine and other nitrogen-containing aromatic compounds can be carried out with olefins and CO, using Ru3(CO)i2 as the catalyst (Scheme 6.16). Interestingly, internal olefins, such as cis- and frawi-2-hexene, yield the same linear/branched product ratio as terminal olefins. 

N- [4-[ 1 -Ethyl-2-(2,4-diaminofuro[2,3-d]pyrimidin-5-yl)ethyl]benzoyl]-L-glu-tamic acid as an antifolate was synthesized by Gangjee and colleagues [107], and palladium-catalyzed alkoxycarbonylation of aryl triflate was applied. A palladium-mediated carbonylative C-H activation was developed by Sames and team and applied in the total synthesis of teleocidin B4 core (Scheme 10.24) [108]. 

The extensive work carried out by Beller in recent years has contributed to the field with a series of interesting examples, most of them based on the system palladium/di-1 -adamantyl- -butylphosphine (BuPAdj). Thus, they reported the use of ammonia as the nitrogen source for the palladium-catalyzed aminocarbonylation of aryl halides, providing a straightforward method to prepare primary amides with excellent applicability and functional group tolerance [4]. In the same group, the first carbonylative C—H activation reactions of heteroarenes to form diaryl ketones 4 were developed [5], A series of nonpreactivated heteroarenes 3 (oxazoles, thiazoles, and imidazoles) were successfully carbonylative coupled to a wide range of aryl iodides (Scheme 3.2). To avoid the formation of the noncarbonylative... 

Cobalt-Catalyzed Heterocyclic Synthesis via Carbonylative C-H Activation 15.2.1... 

Palladium-Catalyzed Heteroqfclic Synthesis via Carbonylative C-H Activation 477 Table 15.9 Selected examples for the carbonylative isoquinoline-1,3(2H,4H)-dione... 

Palladium-Catalyzed Heterocyclic Synthesis via Carbonylative C-H Activation 491 Table 15.24 Selected examples for the carbonylative synthesis of quinazolin-4(3H)-onesl. ... 

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