Palladium(0)‐Catalyzed Amino‐Heck Reaction of γ,δ‐Unsaturated Ketone N,N,N‐Trimethylhydrazonium Salts.

Abstract

Pyrrole derivatives R 0120Palladium (0)-Catalyzed Amino-Heck Reaction of γ,δ-Unsaturated Ketone N,N,N-Trimethylhydrazonium Salts. -γ,δ-Unsaturated ketone hydrazonium salts undergo Pd(0)-catalyzed N-N bond scission and cyclization to 2,5-disubstituted pyrroles. Interestingly, in the presence of molecular sieves, the isomerization of the preliminary cyclization product (VIII) is prevented. -(KITAMURA, M.; YANAGISAWA, H.; YAMANE, M.; NARASAKA*, K.; Heterocycles 65 (2005) 2, 273-277; Dep. Chem., Grad. Sch. Sci., Univ. Tokyo, Bunkyo, Tokyo 113, Japan; Eng.) -Mais 24-107

Cross-Coupling of Heteroatomic Electrophiles

“…In addition to the traditional pentafluorobenzoyloxime ester substrates that are a hallmark of the Narasaka–Heck reaction (see section ), Narasaka also found that N , N , N -trialkylhydrazonium salts can also react with palladium(0) in a similar transformation . When the benzophenone derived hydrazonium 369 was subjected to a Pd(0) source in deuterated DMF, the trimethylamine signal of the starting material disappeared and a new signal appeared upfield.…”

“…In addition to the traditional pentafluorobenzoyloxime ester substrates that are a hallmark of the Narasaka− Heck reaction (see section 3.2.1), Narasaka also found that N,N,N-trialkylhydrazonium salts can also react with palla-dium(0) in a similar transformation. 324 When the benzophenone derived hydrazonium 369 was subjected to a Pd(0) source in deuterated DMF, the trimethylamine signal of the starting material disappeared and a new signal appeared upfield. He suggests that the shift of this upfield signal is more indicative of either free trimethylamine, the trimethylamine hydrochloride salt, or a trimethylamine bound to a palladium-(II) species rather than a hydrazine species.…”

Multi‐Component Reaction of 6‐Aminouracils, Aldehydes and Secondary Amines: Conversion of the Products into Pyrimido[4,5‐d]pyrimidines through C‐H Amination/Cyclization

“…[2] Pyrimidopyrimidines have attracted considerable attention in medicinal chemistry due to their potential and diverse biological activities such as antiviral, [3] antitumor, [4] antimicrobial, [5] and anti-allergic effects. [6] Few bioactive pyrimido [4,5-d]pyrimidines are shown in Figure 1. [7] Pyrimido [4,5-d]pyrimidines were synthesized earlier by several research groups using amines other than cyclic one.…”