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
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
Camphor-based Schiff base ligand SBAIB: an enantioselective catalyst for addition of phenylacetylene to aldehydes
作者:Ramalingam Boobalan、Chinpiao Chen、Gene-Hsian Lee
DOI:10.1039/c1ob06683h
日期:——
series of Schiffbase ligands were synthesized from (1R)-camphor. Under the optimal conditions, (+)-SBAIB-a, 10 was found to be an excellent catalyst for the enantioselective addition of phenylacetylene to various aldehydes without utilizing either achiral additives or Ti(OiPr)4. This approach yielded (R)-propargylic alcohols in extremely high yields (up to 99%) and excellent enantioselectivities (up to
从中合成了一系列席夫碱配体 (1 R)-樟脑。在最佳条件下(+)-SBAIB-a,10被发现是用于对映选择性加成的极好的催化剂苯乙炔 无需使用非手性添加剂或 钛(O i Pr)4。该方法以极高的产率(高达99%)和优异的对映选择性(高达92%)产生了(R)-丙炔醇。相应的(S)-丙炔醇的合成具有良好的对映选择性(高达91%)和极好的收率(高达99%),使用(-)-SBAIB-a,41岁。
Asymmetric transfer hydrogenation of unsaturated ketones; factors influencing 1,4- vs 1,2- regio- and enantioselectivity, and alkene vs alkyne directing effects
作者:Thomas H. Hall、Hannah Adams、Vijyesh K. Vyas、K.L. Michael Chu、Martin Wills
DOI:10.1016/j.tet.2020.131771
日期:2021.1
A detailed study has been completed on the asymmetric transferhydrogenation (ATH) of a series of enones using Ru(II) catalysts. Electron-rich rings adjacent to the CO group reduce the level of CO reduction compared to CC. The ATH reaction can readily discriminate between double and triple bonds adjacent to ketones, reducing the double bond but leaving a triple bond intact in the major product.
Highly Enantioselective Phenylacetylene Additions to Both Aliphatic and Aromatic Aldehydes
作者:Ge Gao、David Moore、Ru-Gang Xie、Lin Pu
DOI:10.1021/ol026921r
日期:2002.11.1
The readilyavailable and inexpensive BINOL in combination with Ti(O(i)Pr)(4) is found to catalyze the reaction of an alkynylzinc reagent with various types of aldehydes including aliphaticaldehydes, aromaticaldehydes, and other alpha,beta-unsaturated aldehydes to generate chiral propargyl alcohols with 91-99% ee at room temperature. No previous chiral catalysts have exhibited such a broad scope