Proline-catalyzed aldol reactions of acyl cyanides with acetone: an efficient and convenient synthesis of 1,3-diketones
作者:Zongxuan Shen、Bin Li、Lu Wang、Yawen Zhang
DOI:10.1016/j.tetlet.2005.10.036
日期:2005.12
The aldol-type addition of acetonetowards (un)substituted benzoyl, heteroarylcarbonyl or α,β-unsaturated acyl cyanides was efficiently catalyzed by l-proline (30 mol %) to give 2-hydroxy-4-oxo-2-substituted pentanenitriles. Upon the treatment with sodium hydroxide, the adducts transformed to 1,3-diketones in good-to-excellent yield, furnishing an efficient and convenient method for the regioselective
Borohydrideexchangeresin (BER) exhibited selectivity in the reduction of α, β-unsaturated carbonyl compounds to the corresponding unsaturated alcohols.
Synthesis of polysubstituted cyclopenta[b]indoles via relay gold(<scp>i</scp>)/Brønsted acid catalysis
作者:Seema Dhiman、S. S. V. Ramasastry
DOI:10.1039/c4cc08174a
日期:——
various polysubstituted cyclopentannulated indoles from easily accessible 1-(2-aminophenyl)prop-2-ynols and readily available 1,3-dicarbonyls has been developed. In an unprecedented event, the intermediate 2-indolylmethyl cations undergo the cation-Ene reaction with various 1,3-dicarbonyls followed by an intramolecular Friedel-Crafts-type reaction generating functionalized cyclopenta[b]indoles.
α-Diazo-β-hydroxyketones, obtained by condensation of aldehydes with 1-diazo-1-lithioacetone, are efficiently transformed into the corresponding β-diketones by exposure to rhodium(II) acetate. The sequence is applied to a new synthesis of β-damascone (10).