40238-92-4

Upstream product

• 4376-23-2 (E)-hex-3-en-2-one 
• 920-39-8 isopropylmagnesium bromide 
• 1669-43-8 (E)-4-isopropylbut-3-en-2-one 
• 557-20-0 diethylzinc 
• 97-93-8 triethylaluminum 
• 5166-53-0 5-methyl-3-hexene-2-one 

Relevant academic research and scientific papers

Amino-sugar modular ligands - Useful cores for the formation of asymmetric copper 1,4-addition catalysts

Modular phosphine ligands, synthesised rapidly from commercial N-acetylglucosamine, are very effective in copper(I)-catalysed 1,4-additions of ZnR2 to linear aliphatic enones (87-95% ee). The Royal Society of Chemistry.

Enantioselective copper catalysed 1,4-conjugate addition reactions using chiral N-heterocyclic carbenes

The preparation of a variety of chiral N-heterocyclic carbene (NHC) precursors is described. The relative merits of imidazolinium salts and silver carbenes as NHC precursors are discussed with respect to their synthesis, stability and performance in the copper catalysed conjugate addition of dialkyl zinc reagents to a variety of Michael acceptors. Enantioselectivities of up to 93% were achieved using as little as 4% of chiral ligand.

Copper-catalysed asymmetric conjugate addition of organometallic reagents to linear enones using thiourethane ligands

In the presence of chiral thiourethane ligands [Cu(MeCN)4]BF4 forms active catalysts for the conjugate addition of MeMgBr, ZnEt2 and AlR3 (R = Me, Et) to non-3-en-2-one, hept-3-en-2-one, and 5-methylhex-3-en-2-one. Enantioselectivities of up to 51% are realised for these difficult substrates; for cyclohex-2-enone an e.e. of 42% is attained.

Acceleration of the conjugate addition of diethyl zinc to enones by either Cu(OTf)2 or trivalent phosphorus ligands

The conjugate addition of diethyl zinc to enones under copper catalysis occurs well with copper (II) trifiate. Other copper salts need a phosphine or phosphite ligand to be efficient. The best combination is copper (II) triflate and triethyl phosphite. A very small amount of copper (II) triflate (0.5%) and triehtyl phosphite (1%) are enough for high yields.

Mechanism of the Grignard Adddition Reaction. XVI. Homolytic and Concerted Mechanisms in the Reaction of α,β-Unsatureted Carbonyl Compounds with Grignard Reagents

Kinetic measurements have shown that the addition of Grignard reagents to α,β-unsaturated carbonyl compounds takes place either by a concerted mechanism or by a homolytic mechanism.Phenylmagnesium bromide, which is incapable of homolysis, reacts rapidly in a 1,4-fashion if an s-cis conformation exists between the C=C and the C=O bonds, but only 1,2-addition takes place if the conformation is s-trans.tert-Butylmagnesium bromide is unsuited to the concerted reaction, but 1,4-addition takes place via homolysis.Primary and secondary Grignard reagents, like phenyl, react rapidly in a concerted manner with s-cis substrates, but unlike phenyl, these Grignard reagents may, with s-trans substrates, produce some 1,4-adduct via the homolytic mechanism.