Acrolein complexes with copper

The complexes are isolated, characterized and used as chiral Lewis acids. Dissociation of the labile ligand liberates a single coordination site at the metal center. These Lewis acids catalyze enantioselective Diels-Alder reactions. For instance, reaction of methacrolein with cyclopentadiene in the presence of the cationic iron complex (L = acrolein) occurs with exo selectivity and an enantiomeric excess of the same order of magnitude as those obtained with the successful boron and copper catalysts (eq 3). ... 

Several complexes of cuprous halides with acrylonitrile 69> and acrolein 70> have been investigated. The enthalpies of complexing have been found from vapour pressure measurements the enthalpy of formation of the complex from solid copper chloride and liquid acrylonitrile was -29.3 kJ mole-1, while with copper bromide this was -1.3 kJ mole-1. The corresponding value for the acrolein complex was -17.3 kJ mole-1 the enthalpy values for the formation from the gaseous olefinic compounds were -62.3, -34.3 and -49.2 kJ mole-1 respectively. 

The olefin complexes of these metals are often readily decomposed in aqueous solution and Cu(I)-olefin complexes are conveniently prepared by reduction of ethanolic solutions of copper(II) halides and the olefin with SO2 [73]. Distribution studies of olefins between carbon tetrachloride and aqueous solutions of silver and copper salts show that the Cu(I)-olefin complexes hav6 considerably higher stability constants than the analogous silver complexes [74]. Evidence for a relatively weak olefin-metal bond in the complexes of both metals comes from infrared and Raman spectra which show that usually the stretching frequency of the co-ordinated C=C is lowered by only 50-60 cm i compared with a lowering of > 120 cm i found for most olefin-platimun complexes. In the acrolein complex [(CHj=CHCHO)CuCflj the C=C stretch is lowered by 90 an [74fl]. 

As a primary amine, monoethanolamine will react with aldehydes and ketones to yield aldimines and ketimines. Additionally, monoethanolamine will react with aluminum, copper, and copper alloys to form complex salts. A violent reaction will occur with acrolein, acrylonitrile, epichlorohy-drin, propiolactone, and vinyl acetate. 

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