Amination rhodium catalysed

LFP studies of the N-H insertion of silylenes have shown that the reaction proceeds by formation of an acid - base complex at almost a diffusion rate with a noticeable dependence of the steric hindrance of the amine. Rhodium-catalysed hydrosilyation of ketones by diphenylsilane has been found to occur via the intermediacy of the rhodium silylene (158). ... 

Carbenoid additions to y,y-difluoroallylic compounds represent valuable methodology complementary to the difluorocarbene chemistry described in Sect. 2.1. One example was provided by Boger and Jenkins [353] at Scripps during a synthesis of a duocarmycin analogue. Intramolecular rhodium-catalysed carbenoid addition of a p-quinonediazide to a protected difluoroallylic amine formed a key intermediate (Eq. 137). 

Rhodium-catalysed hydroboration is a powerful tool for introducing chirality into a styrene-derivative. (Figure 1.1)[2] This was in competition to the established route based on chiral resolution using separation of diastereomers formed from reaction of the racemic amines with homo-chiral acids (natural pool). However, although the process appeared favourable from the chemical synthetic route, the process was practically impossible owing to there being no supplier of catecholborane on large scale at the time. 

In the presence of a strongly basic amine, rhodium complexes are found to catalyse selective hydrogenation of cinnamaldehyde to cinnamyl alcohol. Hydrogenation of aliphatic unsaturated aldehydes under the same conditions gives poor selectivity. ... 

Rische T, Eilbracht P (1999) One-pot synthesis of pharmacologically active secondary and tertiary l-(3,3-diarylpropyl)amines via rhodium-catalysed hydroaminomethylation of 1,1-diarylethenes. Tetrahedron 55 1915-1920... 

Among reactions of phosphines occurring in the coordination sphere of a transition metal are a rhodium-catalysed hydrogenation and silylation of P-P bonds to give secondary phosphines and silylphosphines, a chiral amine-palladium template-promoted asymmetric cycloaddition of phenyldivinylphosphine to 3,4-dimethyl-1-phenylarsole to give the chiral... 

A range of cyclic ketimines (38, X = CH2, O, NR) undergo rhodium-catalysed asymmetric arylation to give gem-diaryl sulfamidates or sulfamides (39) in up to 99% ee. The products can be converted into a-tertiary chiral amine derivatives without loss of enantiomeric purity. 

Initially, carbonylation of unactivated alkanes sp C-H bonds to produce aldehydes has been performed by Tanaka in the presence of rhodium catalyst tmder photochemical irradiation [6]. The Chatani-Kakiuchi-Murai group also performed the rhodium-catalysed monocarbonylation of sp C-H bond adjacent to the nitrogen atom of cyclic amines and directed by a pyridine group in the presence of ethylene to produce a-propanoyl amines [7]. It is only very recently in 2011 that Chatani has... 

As another extension of this process, Davies et al. have developed highly regio-, diastereo- and enantioselective C-H insertions of methyl aryldiazoace-tates into cyclic A-Boc-protected amines catalysed by rhodium(II) S)-N- p-dodecylphenyl)sulfonylprolinate. The best results were obtained in the case of the C-H insertion of methyl aryldiazoacetates into A-Boc-pyrrolidine, which gave, in all cases, a diastereoselectivity and an enantioselectivity greater than 90% de and 90% ee respectively (Scheme 10.77). The synthetic utility of this method was demonstrated by means of a two-step asymmetric synthesis of a novel class of C2-symmetric amines. 

The reaction of alcohols with CO can also be catalysed by palladium iodides, and various ligands or solvents. Acetic acid is prepared by the reaction of MeOH with CO in the presence of a catalyst system comprising a palladium compound, an ionic iodide compound, a sulfone solvent at conditions similar to those of the rhodium system (180 °C, 60 bar), and, in some cases, traces of a nickel-bipyridine compound were added. Sulfones or phosphine oxides play a stabilising role in preventing metal precipitation [26], Palladium(II) salts catalyse the carbonylation of methyl iodide in methanol to methyl acetate in the presence of an excess of iodide, even without amine or phosphine co-ligands platinum(II) salts are less effective [27],... 

An ab initio method has been employed to study the mechanism of the thermal isomerization of buta-1,2-diene to buta-1,3-diene. The results of the study have indicated619 that the transformation proceeds in a stepwise manner via a radical intermediate. Experimental free energies of activation for the bond shift in halocyclooctatetraenes have been reported and analyzed by using ab initio MO calculations.620 The isomerization of hexene using a dihydridorhodium complex in dimethyl sulfoxide has been reported,621 and it has been suggested622 that the Pd(II)-catalysed homogeneous isomerization of hexenes proceeds by way of zr-allylic intermediates. A study has been made623 of alkene isomerization catalysed by the rhodium /-phosphine-tin dichloride dimeric complex, and the double-bond isomerization of olefinic amines over potassium amide loaded on alumina has been described.624... 

Substituted bicyclo[ . 1.0]alkanes may also be obtained by condensation of secondary amines with 2-haloketones. A variety of nucleophilic reactions can be carried out on the intermediate cyclopropaniminium salt 116251 (Scheme 108). Competing alkene scission and cyclopropanation occurs on reaction of enamines with pentacarbonyl-chromium carbene complexes252 (Scheme 109). N-Silylated allylamines and their derived N-silylated enamines undergo rhodium or copper catalysed cyclopropanation by methyl diazoacetate253 (Scheme 110). 

The greater part of this chapter is concerned with the Diels-Alder and hetero-Diels-Alder reaction. The asymmetric version of both of these reactions can be catalysed with metal-based Lewis acids and also organocatalysts. The catalytic asymmetric 1,3-dipolar cycloaddition of nitrones and azomethine ylides is also discussed. Again, most success in this area has been achieved using metal-based Lewis acids and the use of organocatalysts is begiiming to be explored. This chapter concludes with a brief account of recent research into the asymmetric [2+2]-cycloaddition, catalysed by enantiomerically pure Lewis acids and amine bases, and also the Pauson-Khand [2- -2- -l] cycloaddition mediated by titanium, rhodium and iridium complexes. 

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