Carboxamides, diene

Hydroaminomethylahon of alkenes [path (c)j wiU not be considered [12]. This review deals exclusively with the hydroaminahon reaction [path (d)], i.e. the direct addition of the N-H bond of NH3 or amines across unsaturated carbon-carbon bonds. It is devoted to the state of the art for the catalytic hydroamination of alkenes and styrenes but also of alkynes, 1,3-dienes and allenes, with no mention of activated substrates (such as Michael acceptors) for which the hydroamination occurs without catalysts. Similarly, the reachon of the N-H bond of amine derivatives such as carboxamides, tosylamides, ureas, etc. will not be considered. 

Several cationic palladium(II) aqua complexes, [Pd(H20)4], cis-[PdL(H20)2] (L = en, methionine methyl ester, l,5-dithiacycloocta-3-ol), and [Pd(dien)(H20)], serve as the active catalyst for the selective hydration of various nitriles to the corresponding carboxamides, e.g., CHCI2CN was hydrated to CHCl2C(0)NH2 in the presence of... 

Thiophenes can function either as a diene or as a dienophile in an intramolecular Diels-Alder reaction (90CC405). The 7V-(2-thienyl)allene carboxamide (182) on heating at 130°C leads to (183) by a [4 + 2] cycloaddition in which the thiophene functions as a 4ir component, followed by the usual extrusion of sulfur. 

The Bi(OTf)3-Cu(CH3CN)4PF6 system has been reported to promote efficiently an intermolecular 1 1 hydroamination of 1,3-dienes R1CH=CHCH=CHR2 with various carbamates, sulfonamides, and carboxamides to afford allylic amines in Markovnikov... 

JOC3757>. Dirhodium(ll) carboxamidate complexes <2004AGE2665> and dendritic titanium(rv) complexes <2003CEJ5989> are also excellent catalysts for the hDA reaction between Danishefsky s diene and aldehydes leading to enantioenriched tetrahydropyran-4-ones. 

Mild and selective 1 1 reactions of amines with 1,3-dienes without telomer-ization are still limited. The recently reported bismuth-catalyzed intermolecular hydroamination with various amides (carbamates, sulfonamides, and carboxamides) to produce allylic amines in good yields is a good example of such a reaction (Equation 56 and Scheme 11.4) [80]. Some additives are necessary to optimize the reaction conditions. Cyclic and acyclic dienes were tested. The isomer ratio (1,2-adduct versus 1,4-adduct) depended on the nature of the dienes. 

In the hydroamination of unsaturated carbon-carbon bonds, gold catalysts play an important role. Intermolecular hydroamination of alkenes [177], 1,3-dienes [204], terminal and internal alkynes [205], and allenes [206] are known to proceed smoothly in the presence of PhsP AufI) or AuCls catalyst. In addition, amino olefins also efficiently undergo intramolecular hydroamination using similar gold catalysts. He and coworkers have developed the catalytic cycloaddition of tosylated amino olefins [207], A representative example is shown in Scheme 18.35. When N-tosylated y-amino olefin (97) is exposed to a mixture of PhsP AuCl and AgOTf (5 mol% each) in toluene at 85 °C, pyrrolidine (98) is obtained in 96% yield. The gold(I)-catalyzed intramolecular hydroamination is applicable to N-alkenyl carbamates [208], N-alkenyl carboxamides [209], and N-alkenyl ureas [210], The use of microwave irradiation results in completing the hydroamination in a much shorter time than that required under thermal reaction conditions [211], The... 

Tian M, He Y, Zhang X, Fan X (2015) Synthesis of Pyrazolo[5,l-a]isoindoles and Pyrazolo [5,l-a]isoindole-3-carboxamides through one-pot cascade reactions of l-(2-Bromophenyl) buta-2,3-dien-l-ones with isocyanide and hydrazine or acetohydrazide. J Org Chem 80 (15) 7447-7455... 

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