Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Rhodium nitrogen containing

As another way of constructing nitrogen-containing heterocycles enantioselec-tively, the use of 3-aIkoxycarbonyl-3-pyrrolines as substrates has also been described in the rhodium-catalyzed asymmetric 1,4-addition reactions (Figure 3.41). Among the conditions examined, it was found that [Rh(OH)(cod)]2/(5)-binap catalyst is uniquely effective for achieving high yield of the 1,4-adducts. [Pg.86]

Evans et al. have recently demonstrated a highly enantioselective synthesis of allyl amines 52 from enantiomerically pure carbonates 51 catalyzed by rhodium complexes (Eq. (13)) [33], The reaction proceeds with excellent regioselectivities, and the allyl amines are isolated in high yields and with a high degree of conservation of the optical purity. The scope of this reaction is demonstrated by the synthesis of, e.g., optically active nitrogen-containing heterocycles. [Pg.15]

Expansion of aziridines to -lactams. This rhodium complex catalyzes a regio-specific carbonylation of N-f-butyl-2-arylaziridines (1) to form lactams (2). The reaction fails if the alkyl group on nitrogen contains acidic hydrogens adjacent to nitrogen. [Pg.112]

It should be noted that related coupling reactions have been developed for aromatic compounds having carbonyl- and nitrogen-containing functional groups with unsaturated compounds, especially by using ruthenium and rhodium catalysts, which involve precoordination of the neutral functional groups followed by ortho-C-H activation [7,9,153,154]. [Pg.78]

Abstract Carbon d ylide dipoles are important intermediates with great application in heterocyclic chemistry. Here, we show how the rhodium-catalyzed a-diazocarbonyl compounds are employed in the generation of carbonyl ylides and their effective use for the synthesis, as well as functionalization, of heterocycles. Herein we discuss recent advancements in this field mainly describing the synthesis and importance of various oxygen-and nitrogen-containing heterocyclic systems and natural products from a-diazocarbonyl compounds. [Pg.156]

Herein rhodium-catalyzed inter- and intramolecular cycloadditions of carbonyl ylides derived from a range of diazocarbonyl compounds leading to oxygen- and nitrogen-containing heterocyclic systems and natural products are discussed. We have focussed on the last five years for the most significant developments of the reactions of carbonyl ylides derived from diazocarbonyl compounds. [Pg.157]

Rhodium(ii) carboxylates are reported to be highly efficient catalysts for the cyclopropanation of alkenes with alkyl diazoacetates. Yields are improved from the procedure using copper trifluoromethane sulphonate. The catalytic co-oligomerization reactions of butadiene with various nitrogen containing moieties was extended and can clearly lead to interesting functionalized molecules (Scheme... [Pg.29]

A new rhodium complex with a nitrogen-containing bis(phosphane oxide) ligand (28) was applied to hydroformylation of styrene. High activity (TON up to 1443 mol aldehyde/mol catalyst) and regioselectivity toward the branched aldehyde (96.9%) were found at 30-40 °C and 20-100bar CO H2 = 1 1 [53]. [Pg.171]


See other pages where Rhodium nitrogen containing is mentioned: [Pg.165]    [Pg.1354]    [Pg.429]    [Pg.13]    [Pg.197]    [Pg.437]    [Pg.108]    [Pg.1180]    [Pg.86]    [Pg.235]    [Pg.111]    [Pg.176]    [Pg.237]    [Pg.137]    [Pg.1067]    [Pg.382]    [Pg.778]    [Pg.733]    [Pg.638]    [Pg.77]    [Pg.17]    [Pg.577]    [Pg.615]    [Pg.633]    [Pg.649]    [Pg.345]    [Pg.278]    [Pg.207]    [Pg.193]    [Pg.377]    [Pg.128]    [Pg.140]    [Pg.282]    [Pg.124]    [Pg.938]    [Pg.1518]    [Pg.334]    [Pg.70]    [Pg.333]    [Pg.239]    [Pg.42]    [Pg.172]   
See also in sourсe #XX -- [ Pg.887 , Pg.978 ]




SEARCH



Contain Nitrogen

Containers nitrogen

Nitrogen-containing

© 2024 chempedia.info