Hydrazines, Heck reactions with

Condensation of resin bound ketones with hydrazines followed by cyclizative cleavage was used in a synthesis of pyrazolinones [67]. Samarium iodide induced radical cyclization of allyl aryl ethers led to benzofuran derivatives [68]. Kurth et al. have reported a two reaction iterative process for the construction of polyisoxazolines [69] and polyisoxazoles [70]. An intramolecular Heck reaction has been employed to prepare 2-oxindole derivatives [71]. 

Reaction of 6-halopurines with Michael acceptors under Heck conditions gives N- -substituted hypoxanthine derivatives <00CCC797>. Reactions of a series of 1-aminobenzimidazoles and l-amino-3-methylbenzimidazolium chlorides with 2,4-pentanediones afford pyridazino[l,6-a]benzimidazoles and 2-pyrazolylanilines, the product ratio depending on conditions and on the electronic character of the substituents at the benzene moiety <00BMC37>. Cyclization reactions of adenine derivative 75 with different amines or hydrazine afford tricyclic polyaza compounds 76 <00CCC1109>. 

Palladium-catalysed Heck-type reaction of ort/io-functionalized aryl iodides (75) with bicyclic hydrazines (76) has been designed as a facile route towards heteroannulated cyclopentenes (77)7 ... 

Palladium-catalyzed cross-coupling reactions of aryl chlorides 5 with hydrazine afforded intermediate arylhydrazines 6 at ambient temperatures, which reacted further with P-diketones to give 1,3,5-trisubstituted pyrazoles 7 in one-pot (13AG(E)3434). Palladium-catalyzed Heck car-boxylative cross-coupling reactions of aryl iodides with acetone afforded the in situ 1-aryl-1,3-butadiones, which reacted with an aqueous solution of hydrazine in ethanol to give 3-methyl-5-arylpyrazoles in moderate yields (13CEJ12624). 

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