Highly Enantioselective Catalytic Alkyl Propiolate Addition to Aliphatic Aldehydes
作者:Mark Turlington、Albert M. DeBerardinis、Lin Pu
DOI:10.1021/ol900667g
日期:2009.6.4
A novel H8BINOL-based chiral ligand (S)-3 is found to catalyze the alkyl propiolate addition to aliphatic aldehydes in the presence of ZnEt2 and Ti(OiPr)4 at room temperature with excellent enantioselectivity (89−97% ee).
发现一种新型的基于H 8 BINOL的手性配体(S)-3在室温下在ZnEt 2和Ti(O i Pr)4的存在下以优异的对映选择性(89-97%)催化丙酸烷基酯加成到脂肪族醛中ee)。
Mg(OMe)<sub>2</sub> promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters to synthesize γ-ketone esters
作者:Luhao Lai、A-Ni Li、Jiawei Zhou、Yarong Guo、Li Lin、Wei Chen、Rui Wang
DOI:10.1039/c7ob00131b
日期:——
This work concerns the Mg(OMe)2 promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters with TMEDA as an additive. The isomerization proceeded under mild conditions and afforded γ-keto esters in high yield (up to 96%) within 2 h. Both (Z)- and (E)-γ-hydroxy-α,β-alkenoic esters were tolerated under the reaction conditions. This transformation involves the in situ formation of a dienolate intermediate
3,3′-Anisyl-Substituted BINOL, H<sub>4</sub>BINOL, and H<sub>8</sub>BINOL Ligands: Asymmetric Synthesis of Diverse Propargylic Alcohols and Their Ring-Closing Metathesis to Chiral Cycloalkenes
作者:Yang Yue、Mark Turlington、Xiao-Qi Yu、Lin Pu
DOI:10.1021/jo9018446
日期:2009.11.20
aldehydes. It catalyzed the reactions of alkyl propiolates with 88−99% ee; the reactions of phenylacetylene with 81−87% ee; the reactions of 4-phenyl-1-butyne, an alkyl alkyne, with 77−89% ee; and the reactions of trimethylsilylacetylene with 92−97% ee. The optically active propargylic alcohols generated from this catalytic asymmetric alkyne addition were observed to undergo efficient ring-closing-metathesis
Cyclic acetal formation between 2-pyridinecarboxyaldehyde and γ-hydroxy-α,β-acetylenic esters
作者:Sami Osman、Kazunori Koide
DOI:10.1016/j.tetlet.2008.09.008
日期:2008.11
A new transformation between 2-pyridinecarboxyaldehyde and gamma-hydroxy-alpha,beta-acetylenic esters to form highly functionalized cyclicacetals was discovered. This transformation proceeds under very mild conditions without any additives and is promoted by the basic nature of the pyridine ring.
This invention relates to a process for preparation of the compounds of lignan series in a regioselective manner. This invention provide a process for preparing a compound of the formula (I): which process is characterized by that a lactone compound represented by the formula (II) is allowed to react with a compound of the formula: R.sup.7 Cl in the presence of a base, then the resulting compound is subjected to addition reaction with an acetylenic compound of the formula (III), then the resulting compound is reduced; in which R.sup.1 is alkyl, cycloalkyl, cycloalkyl lower alkyl, or aralkyl and the like; R.sup.2 and R.sup.3 each is lower alkoxy and the like; R.sup.4 is lower alkoxy or hydrogen; and R.sup.5 and R.sup.6 each is lower alkyl; and R.sup.7 is tri(lower alkyl)silyl. ##STR1##