A new catalytic process for allyl ester cleavage has been developed by using a robust cationic CpRu(IV) π-allyl complex of 2-quinolinecarboxylic acid that can be stored for over six months in air without any loss of catalytic activity. The deprotection of various alcohols and acids can be attained simply with high reactivity and chemoselectivity under mild conditions. Furthermore, with continuous removal
Catalytic Removal of <i>N</i>-Allyloxycarbonyl Groups Using the [CpRu(IV)(π-C<sub>3</sub>H<sub>5</sub>)(2-quinolinecarboxylato)]PF<sub>6</sub> Complex. A New Efficient Deprotecting Method in Peptide Synthesis
N-allylation from the corresponding N-allyloxycarbonyl (N-AOC) compounds by using a catalytic amount of [CpRu(IV)(π-C3H5)(2-quinolinecarboxylato)]PF6 in the presence of 1 molar amount of trifluoromethanesulfonic acid, the general utility of which has been demonstrated by the efficient synthesis of a collagen protein unit tripeptide, Pro-Pro-Gly.
通过使用催化量的[CpRu(IV)(π-C),即使在空间上要求不高且亲核性很高的仲胺等各种胺也无需从相应的N-烯丙氧羰基(N -AOC)化合物上脱羧化N-烯丙基化,即可有效地脱保护。在1摩尔量的三氟甲磺酸存在下的3 H 5)(2-喹啉羧基甲酰基)] PF 6,其一般用途已经通过有效合成胶原蛋白单元三肽Pro-Pro-Gly得到了证明。
A Magnetically Separable Heterogeneous Deallylation Catalyst: [CpRu(η<sup>3</sup>-C<sub>3</sub>H<sub>5</sub>)(2-pyridinecarboxylato)]PF<sub>6</sub>Complex Supported on a Ferromagnetic Microsize Particle Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>
The highly reactive and chemoselective homogeneousdeallylation catalyst CpRu(η3-C3H5)(4-substituted-2-pyridinecarboxylato) was immobilized on microsize spherical Fe3O4@SiO2 particles. The resultant heterogeneouscatalyst displays high saturation magnetization, weak coercive forces and high levels of dispersibility. The catalyst has increased the utility of deallylation by allowing the reaction to be
A Mild Ligand-Free Iron-Catalyzed Liberation of Alcohols from Allylcarbonates
作者:André P. Dieskau、Bernd Plietker
DOI:10.1021/ol202270g
日期:2011.10.21
from most carbonates the allyloxy carbonyl protecting groupcan be cleavedunderneutralconditions using metal catalysis. However, most of the catalysts employed to date are based upon precious metals. Herein we present two protocols for the mild Fe-catalyzed liberation of alcohols from allylcarbonates that are characterized by broad functional group tolerance and exclusive chemoselectivity.