Dienes carboamination

An interesting Pd-catalyzed diene carboamination reaction that involves urea-directed C—H activation was recently reported [56]. For example, treatment of N-aryl urea 63 with an activated diene in the presence of 10 mol% Pd(0 Ac) 2,50 mol% TsO H, AC2O, and benzoquinone provided 64 in 90% yield (Eq. (1.29)). The transformation is initiated by directed palladation of the arene by a palladium tosylate complex (formed... 

As this chapter deals with only carboamination reactions for stereoselective C-N bond formation, discussions of alkyne, allene, and diene carboamination reactions are beyond the scope. 

The 1,4-carboamination has been extended to the use of vinyl bromides [37-39]. The use of morpholine or piperidine as the external nucleophile led to a 1,4-addition to the 1,3-diene via a (7r-allyl)palladium intermediate. An example that leads to a carbocyclization via vinylpalladation is shown in Eq.(19). 

Pd-Catalyzed Carboamination Reactions of Alkynes, Allenes, and Dienes... 

Pd-catalyzed Heck-type reaction of a conjugated diene in the presence of an amine leads to a 1,4-carboamination. In the original version the reaction was performed in the presence of a phosphine. Various aryl and vinyl bromides react with a 1,3-diene and an amine in the presence of the palladiumfO) catalyst (usually generated from Pd(OAc)2 and phosphine) to produce 1,4-carboamination products.P One example is given in Eq. 3. 

In another approach for intramolecular 1,4-carboamination of 1,3-dienes an o-iodoaniline was employed as substrate. The use of an o-iodoaniline in the Pd(0)-catalyzed reaction with 1,3-dienes results in a cychzation in the second step (amine attack on the Tr-aUyl complex) with the formation of indohnes. "" This reaction was already described in 1986 by Dieck and was further developed by Larock. Recently, the reaction was apphed to l-sulfonyl-l,3-dienes, which afforded synthetically useful 2-(sulfonylvinyl)indolines 2... 

Carboamination reactions of dienes lead to the efficient construction of heterocyclic ring systems. However, in all cases, nonstereoselective products were obtained. These reactions are also catalyzed by Pd complexes following a typical carboamination reaction mechanism. Initially, these reactions were called metal-catalyzed heteroannula-tions of diene. After the discovery of the carboamination reaction, these types of heterofunctionalization reactions are called 1,2-carboamination reactions. ... 

Houlden CE, Bailey CD, Ford JG, Gagne MR, Lloyd-Jones GC, Booker-Milbum KI. Distinct reactivity of Pd(OTs)2 the intermolecular Pd(II)-catalyzed 1,2-carboamination of dienes. J. Am. Chem. Soc. 2008 13(X31) 10066 10067. 

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