Intermolecular Pauson−Khand Reactions of Cyclopropene: A General Synthesis of Cyclopentanones
摘要:
GRAPHICSThe Pauson-Khand reaction of cyclopropene with a variety of terminal alkynes has been studied. The best reaction conditions involve NMO activation in CH2Cl2 at -35 degreesC. In this way, 3-substituted-bicyclo[3.1.0]hex-3-en-2-ones have been obtained in good to excellent yields. As a synthetic application, several types of substituted cyclopentenones have been prepared from these cycloadducts by protocols involving conjugate addition and reductive ring opening.
Intermolecular Pauson−Khand Reactions of Cyclopropene: A General Synthesis of Cyclopentanones
作者:Iolanda Marchueta、Xavier Verdaguer、Albert Moyano、Miquel A. Pericàs、Antoni Riera
DOI:10.1021/ol016505r
日期:2001.10.1
GRAPHICSThe Pauson-Khand reaction of cyclopropene with a variety of terminal alkynes has been studied. The best reaction conditions involve NMO activation in CH2Cl2 at -35 degreesC. In this way, 3-substituted-bicyclo[3.1.0]hex-3-en-2-ones have been obtained in good to excellent yields. As a synthetic application, several types of substituted cyclopentenones have been prepared from these cycloadducts by protocols involving conjugate addition and reductive ring opening.
Photochemistry of 3-Substituted Bicyclo[3.1.0]hex-3-en-2-ones. Regioselective Synthesis of <i>O</i><i>rtho</i>-Substituted Phenols by Pauson−Khand Reaction
作者:Iolanda Marchueta、Santiago Olivella、Lluís Solà、Albert Moyano、Miquel A. Pericàs、Antoni Riera
DOI:10.1021/ol016506j
日期:2001.10.1
[reaction: see text] 3-Substituted bicyclo[3.1.0]hex-3-en-2-ones 3, easily obtained by Pauson-Khand reaction between terminal alkynes and cyclopropene, have been quantitatively converted into ortho-substituted phenols 4 by irradiation with UV light (350 nm). The kinetics and mechanism of this photochemical process have been studied by means of FT-IR and semiempirical (AM1 3x3 CI) calculations.