Vinyl methyl ketone, complexes with

From the reaction of vinyl methyl ketone with (CH3CN)3M(CO)3, (M = Cr or Mo), King (348) has isolated the complexes, (vinyl methyl ketone)sM, as yellow volatile solids. Although the molybdenum complex... 

The complex OsH(OH)(CO)(P Pr3)2 also reacts with methyl acrylate, methyl vinyl ketone, and allyl alcohol.91 Reaction with methyl acrylate leads to OsH(OH) (COXrf-CH2=CHC02MeXP Pr3)2 containing the olefin trans to the hydride ligand. In solution, this complex releases the olefin to generate the starting complex. The thermodynamic magnitudes involved in the equilibrium have been determined in toluene-t/a by 31P 1H NMR spectroscopy. The values reported are AH° = 17.0 0.5 kcal-mor1 and AS° = 54.0 1.2 cal-K 1-mol 1. In the presence of the methyl vinyl ketone complex OsH(OH)(CO)(P Pr3)2 affords 0sH CHCHC(0) Me (CO)(P Pr3)2 and water, whereas in the presence of allyl alcohol the loss of... 

Another application of the free diamine as a ligand for asymmetric catalysis is the Michael reaction of cyclic p-keto esters with methyl vinyl ketone, which has been accomplished with a nickel(II)- (15,25)-1,2-diaminocyclohexane complex, with ee s up to91%(eq 11). ... 

Diels-Alder reactions of cyclopentadiene and methacrolein with crotonaldehyde are also catalyzed by complexes formed in situ between NbCls or TaCls and bidentate ligands (2 equiv.) such as L-tartrate esters, or a-amino acids (e.g. tryptophan, alanine). Yields with the Ta catalysts are often somewhat better (14-78 %) than with the Nb catalysts. Good exo. endo ratios are obtained but enantioselectivities are still low (7-40 % ee) [185]. Methylrhenium trioxide is an efficient catalyst in these reactions and its best performance is in aqueous solution. Acrolein derivatives and methyl vinyl ketones react with a variety of dienes to give single diastereoisomers in very high yield with as little as 1 % catalyst loading [186]. Examples are shown in Sch. 49. The reaction is sluggish with disubstituted dienophiles and dienes. 

The Ni(0)-mediated coupling reaction could be successfully applied to Vitamin D derivatives. Nickel chloride is reduced with zinc powder in pyridine to nickel(O), and this forms a brick-red complex with the acrylate ester. This, in turn, is smoothly alkylated by the alkyl iodide. The reaction is widely appUcable it can also be carried out successfully with the sulfur dioxide adducts, and ethyl acrylate may be replaced by methyl vinyl ketone as well. 

Methyl vinyl ketone is synthesized industrially by the hydration of vinylacetylene. The reaction is catalyzed by acetates, formates, or sulfates of mercury, silver, cadmium, copper, or zinc in the presence of acids [329,330]. The oxidation of 1-butene to methyl vinyl ketone in 72% yield by the formation of olefin mercuric salt complexes followed by the decomposition of these complexes with acid may become commercially feasible [331]. 

A Pt pincer complex is able to be bonded to the optically active hyperbranched polyglycerol as pendant groups 594. The CD spectra of the polymer complex with different absolute configuration of the monomer units show opposite signs of the peak at 262 nm. The polymer-bonded complex catalyzes asymmetric addition of ethyl a-cyanoacetate to methyl vinyl ketone." " ... 

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