Double Duty for Cyanogen Bromide in a Cascade Synthesis of Cyanoepoxides
作者:Zhou Li、Vladimir Gevorgyan
DOI:10.1002/anie.201006966
日期:2011.3.14
An unprecedented reaction mode of cyanogenbromide has been discovered. Under basic conditions, cyanogenbromide acts as an equivalent of both Br+ and CN− to convert enolizable ketones into the corresponding cyanoepoxides in good yields. This unique reaction mode provides new, one‐pot access to densely substituted cyanoepoxides from easily available ketones (see scheme).
Ruthenium Catalyzed Hydrohydroxyalkylation of Isoprene with Heteroaromatic Secondary Alcohols: Isolation and Reversible Formation of the Putative Metallacycle Intermediate
作者:Boyoung Y. Park、T. Patrick Montgomery、Victoria J. Garza、Michael J. Krische
DOI:10.1021/ja4087193
日期:2013.11.6
Heteroaromaticsecondaryalcohols react with isoprene to form products of hydrohydroxyalkylation in the presence of ruthenium(0) catalysts generated from Ru3(CO)12 and tricyclohexylphosphine, enabling direct conversion of secondary to tertiary alcohols in the absence of premetalated reagents or stoichiometric byproducts. The putative oxaruthenacycle intermediate has been isolated and characterized
of methyl aluminum complexes bearing chiral biphenol-type ligands were found to be highly active catalysts in the asymmetric reduction of heterocyclic ketones (S/C = 100 - 500, ee up to 99%). The protocol is suitable for a wide range of substrates and has a high tolerance to functional groups. The formed 2-heterocyclic-alcohols are valuable buildingblocks in drug discovery or can be used as ligands
Kineticresolution of secondaryalcohols by benzoylation using a phosphinite derivative of (1S,2R)-1-amino-2-indanol as the catalyst was investigated. The aminophosphinite catalyst is effective for the kineticresolution of aryl cycloalkyl carbinols with a small number of examples for organocatalytic kineticresolution to achieve resolution with s = up to 44. Although the benzoylation of phenylalkanols