Catalytic Asymmetric Enyne Addition to Aldehydes and Rh(I)-Catalyzed Stereoselective Domino Pauson–Khand/[4 + 2] Cycloaddition
作者:Wei Chen、Jia-Hui Tay、Jun Ying、Xiao-Qi Yu、Lin Pu
DOI:10.1021/jo3026065
日期:2013.3.15
propargylic alcohols prepared from the catalyticasymmetric enyne addition to aliphatic aldehydes are used to prepare a series of opticallyactive trienynes. In the presence of a catalytic amount of [RhCl(CO)2]2 and 1 atm of CO, the opticallyactive trienynes undergo highly stereoselective domino Pauson–Khand/[4 + 2] cycloaddition to generate opticallyactive multicyclic products. The Rh(I) catalyst
Chiral Macrocycle-Catalyzed Highly Enantioselective Phenylacetylene Addition to Aliphatic and Vinyl Aldehydes
作者:Zi-Bo Li、Tian-Dong Liu、Lin Pu
DOI:10.1021/jo070091j
日期:2007.6.1
The 1,1‘-binaphthyl macrocycle (S)-2 is found to be an excellent catalyst for the alkyne addition to aldehydes. In the presence of (S)-2 (20 mol %) and Me2Zn (2 equiv) in THF at room temperature, the addition of phenylacetylene to linear or branched aliphatic aldehydes and vinylaldehydes gave various propargylic alcohols with 89−96% ee.
Simple Derivatives of Natural Amino Acids as Chiral Ligands in the Catalytic Asymmetric Addition of Phenylacetylene to Aldehydes
作者:Zhi-jian Han、Rui Wang、Yi-feng Zhou、Lei Liu
DOI:10.1002/ejoc.200400595
日期:2005.3
Opticallyactive propargylic alcohols are important chiral building blocks in asymmetricsynthesis, and asymmetric addition of terminal alkynes to aldehydes is one of the most important and interesting procedures by which to prepare these chiral building blocks. In this work we have identified some simple derivatives of (S)-proline and other natural aminoacids as chiral ligands that can be combined
new chiral β-hydroxy amide ligands were synthesized via the reaction of benzyl chloride and aminoalcohols derived from l-tyrosine. The titanium(IV) complex of chiral ligand 8b was found to be an effective catalyst for the asymmetric alkynylation of aliphatic, vinyl and aromatic aldehydes. The propargyl alcohols were obtained in highly enantiomeric excesses (up to 96% ee) under optimized conditions.
Enantioselective Alkynylation of Aromatic Aldehydes: Pyridyl Phenylene Terpeneol Catalysts with Flexible Biaryl Axes
作者:Bernd Goldfuss、Matthias Leven、David Müller
DOI:10.1055/s-0030-1260325
日期:2011.10
Free rotating biarylaxes of pyridyl phenylene terpenols are fixed by zinc cations to give conformationally pure zinc complexes. These zinc alkoxide catalysts provide yields up to 99% and ee values up to 86% in the enantioselectiveaddition of phenylacetylene to aromatic aldehydes. enantioselectivity - biaryls - organometallic reagents - zinc - alkynes