Michael addition, acidic with conjugated nitriles

As a Lewis Acid. CuCl induces photoreaction of conjugated enones with sUyl enol ethers through a Michael addition process, addition of amines to unactivated nitriles" and... 

Thiolates, generated in situ by the action of ammonium tetra-thiomolybdate on alkyl halides, thiocyanates, and disulfides, undergo conjugate addition to a, (1-unsaturatcd esters, nitriles, and ketones in water under neutral conditions (Eq. 10. II).29 Conjugate addition of thiols was also carried out in a hydrophobic ionic liquid [bmim]PF6/water-solvent system (2 1) in the absence of any acid catalyst to afford the corresponding Michael adducts in high to quantitative yields with excellent 1,4-selectivity under mild and neutral conditions (Eq. 10.12). The use of ionic liquids helps to avoid the use of either acid or base catalysts... 

The Michael-type addition, a nucleophilic addition of an anion to the carbon-carbon double bond of an a,(3-unsaturated ketone, aldehyde, nitrile, nitro, sulphonyl, or carboxylic acid derivative, provides a powerful tool for carbon-carbon bond formation. The reaction is most successful with relatively nonbasic ( soft ) nucleophiles such as thiols, cyanide, primary and secondary amines, and P-dicarbonyl compounds. There is often a competition between direct attack on the carbonyl carbon (1,2-addition) and conjugate addition (1,4-addition) when the substrate is an a,(3-unsaturated carbonyl compound. 

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