110366-21-7Relevant articles and documents
Silver(I)-Catalyzed Addition of Phenols to Alkyne Cobalt Cluster Stabilized Carbocations
Valderas, Carolina,Casarrubios, Luis,Lledos, Agusti,Ortu?o, Manuel A.,de la Torre, María C.,Sierra, Miguel A.
, p. 9015 - 9023 (2016/07/06)
A smooth catalytic method to use phenols as the nucleophilic partner in the Nicholas reaction has been developed. The method uses either AgIor AuIcatalysts with AgClO4or AgBF4as the most efficient catalysts tested. Neither additional additives nor cocatalysts were required and the formation of the corresponding phenol adducts occurred in excellent yields. The process has the single limitation of the inability of less nucleophilic phenols (4-nitrophenol) to generate the corresponding adducts. Additionally, the reaction is highly diastereoselective. DFT calculations allow a catalytic cycle to be proposed that involves trimetallic intermediates; the rate-determining step of the reaction is hydroxy-group elimination in a cobalt–silver trimetallic intermediate.
ADDITION OF ORGANOMAGNESIUM REAGENTS TO RING EPOXY-KETONES V. 4,4-DIMETHYL-2,3-EPOXYCYCLOHEXANONE, AND 3,5,5-TRIMETHYL-2,3-EPOXYCYCLOHEXANONE
Sepulveda, Jose,Soriano, Concepcion,Roquet-Jalmar, Joaquin,Mestres, Ramon,Riego, Juan
, p. 189 - 192 (2007/10/02)
Stereoselectivities found for additions of ethynyl, vinyl, and ethylmagnesium bromides to 4,4-dimethylcyclohexanone oxide 4 are in agreement with a biassed 4a conformation of the substrate, and with a torsional strain effect by the oxirane C2-O bond.Thus, a 1:1 mixture is obtained for the small ethynyl group, whereas highly selective cis attack is found for the larger ethyl reagent.Additions to 3,5,5-trimethylepoxycyclohexanone are highly selective for any of the above organomagnesium reagents due to steric hindrance by the axial methyl group at C5, and trans adducts 14, 16 and 18 result, along with a small amount of the cis-ethynyl epoxycyclohexanol 15.Easy trans-hydroxy-epoxy interconversions have been observed for the trans-ethyl adducts 10 and 18, which are obtained along with their respective isomers 12 and 20.
