The Stereochemistry of Organometallic Compounds. LX. Rhodium-Catalyzed Reactions of Hydrogen and Carbon Monoxide With Alkenylanilines

Abstract

Rhodium- catalysed reactions of o- or p- cyano-N-allylanilines with H2/CO give N- arylpyrrolidine aldehydes resulting from a double hydroformylation sequence. In contrast reactions of o- or p-methyl-N-allylanilines or N- allylaniline itself with H2/CO give ' dimeric ' compounds resulting from self-condensation reactions of an initially formed hydroformylation product together with varying amounts of the double hydroformylation product. Similar reactions of o-cyano-N-but-3-enylanilines give low yields of double hydroformylation products and major products arising from hydrogenation or cross coupling of intermediate enamines. The structure of one of these products, N-2-cyanophenyl-5-(N′-2-cyanophenyl-3-methyl-pyrrolidin-2-yl)-1,2,3,4-tetrahydropyridine (17) (IUPAC name: 2-[5-{1-(2-cyanophenyl)-3-methylpyrrolidin-2-yl}-1,2,3,4-tetrahydropyridin-1-yl] benzonitrile ) was confirmed by an X-ray single-crystal structure determination.

Three Approaches to Catalytic Aqueous Organometallic Chemistry Involving Water Soluble Ligands, Some Modified Cyclodextrins as Ligands, and Reactions in an Aluminophosphate Cavity

“…80:20 not significantly different for the 70:30 value commonly obtained from rhodium catalysed hydroformylations of hex-lene in organic solvents. In contrast, similar reaction of the free amine, N-allylaniline in an organic solvent, ethyl acetate (as shown in Figure 2) was shown to be highly regioselective giving products arising from the linear aldehyde only [3]. Attempts to carry out these reactions using sodium p-diphenylphosphinobenzoate as the water solubilising ligands were not successful and the free phosphinoacid was found to have been precipitated during the attempted reaction.…”

“…Hydroformylation of amine salts allows for the possibility of isolating aminoaldehydes (1) as their salts which are not capable of cyclisation. (5) as a mixture of diastereoisomers (80%) [3]. The fonnation of (5) can occur by the route outlined in Figure 2 in which the enamine (4) formed from the tenninal aldehyde (3) adds to its iminium salt tautomer and the resulting…”

“…Heterocyclic formation involves the lone pair of electrons on the nitrogen atom in all cases. We have found that the final products of these reactions can arise from either direct carbonylation [5] [6] or followed by cyclisation to an imine [3] [4] (Figure 1). In order to elucidate details of the mechanism of some of these reactions we were interested in trapping aminoaldehydes (1).…”

“…We have been interested in hydroformylation reactions of unsaturated amines as novel synthetic routes to nitrogen heterocycles [3] [4]. Heterocyclic formation involves the lone pair of electrons on the nitrogen atom in all cases.…”

Toward the synthesis of incargranine B and seneciobipyrrolidine. Synthesis of octahydro‐dipyrroloquinoline skeleton via dipolar cycloaddition/amination sequence

“…Many other approaches to the synthesis of the core structure have been reported in the literature, but essentially they are based on the oxidative transformations of N‐phenylpyrrolidines or the cyclative processes of N‐phenylhomopropargyl amines [7–19]. Of other methods, perhaps, notable are those based on intramolecular dipolar cycloaddition reactions of azomethine ylides which have been explored in the synthesis of martinelline [20–31].…”