475644-63-4Relevant academic research and scientific papers
Rhodium- or copper-catalysed CH-insertion of carbenoids into dihydro-aromatic compounds and acyclic 1,4-dienes
Hilt, Gerhard,Galbiati, Fabrizio
, p. 3589 - 3596 (2006)
A straightforward reaction sequence consisting of a cobalt-catalysed Diels-Alder reaction for the generation of dihydroaromatic compounds and a rhodium- or alternatively a copper-catalysed CH-insertion reaction of carbenoids from diazo esters generates highly substituted benzene derivatives. When acyclic 1,4-dienes are synthesised by a cobalt-catalysed 1,4-hydrovinylation reaction, the rhodium-catalysed conversion with diazo esters leads to cyclopropanation rather than CH-insertion products. Georg Thieme Verlag Stuttgart.
Straightforward synthesis of nonconjugated cyclohex-3-enone and conjugated 4-methylenecyclohex-2-enone derivatives
Kuttner, Julian R.,Warratz, Svenja,Hilt, Gerhard
experimental part, p. 1293 - 1303 (2012/06/30)
The synthesis of nonconjugated cyclohex-3-enones via the regiodivergent cobalt-catalysed Diels-Alder reactions of 2-(trimethylsilyloxy)buta-1,3-diene with alkynes and hydrolysis of the dihydroaromatic intermediates is described. The application of bidentate phosphine ligands versus pyridine-imine ligands led to the regioselective formation of one out of the two possible regioisomeric products when terminal or unsymmetrically substituted alkynes were applied. The cyclohex-3-enone products were isolated mostly in good yields without isomerisation of the carbon-carbon double bond into conjugation based on the mild reaction conditions. The use of acetoxymethyl-substituted alkynes led to the conjugated 4-methylenecyclohex-2-enones after deprotection of the silyl enol ether. Georg Thieme Verlag Stuttgart · New York.
Cobalt(I)-catalyzed neutral Diels-Alder reactions of oxygen-functionalized acyclic 1,3-dienes with alkynes
Hilt, Gerhard,Smolko, Konstantin I.,Lotsch, Bettina V.
, p. 1081 - 1084 (2007/10/03)
The cobalt-catalyzed Diels-Alder reaction of alkoxy-substituted 1,3-butadienes with terminal and internal alkynes is described. While the reaction of 1-alkoxy derivatives gave the aromatic hydrocarbons upon elimination of alcohol from the alkoxy-substituted dihydroaromatic intermediates, the reactions with 2-alkoxy derivatives generated stable dihydroaromatic enol ethers in good to excellent chemical yields and good to high regioselectivities for unsymmetrical starting materials. The enol ethers can be easily hydrolysed to the corresponding β,γ-unsaturated ketones in a one pot reaction sequence or used in cyclopropanation or other subsequent chemical transformations.
