Enantioselective Rh-Catalyzed Anti-Markovnikov Hydroformylation of 1,1-Disubstituted Allylic Alcohols and Amines: An Efficient Route to Chiral Lactones and Lactams
Rh-catalyzed highly enantioselective anti-Markovnikov hydroformylation of 1,1-disubstituted allylic alcohols and amines has been achieved. By using a chiral hybrid phosphorus ligand, a series of challenging 1,1-disubstituted allylic alcohols and amines were transformed to valuable chiral lactones and lactams with good yields and high enantioselectivities (up to 90% yield and 93% enantiomeric excess
已经实现了Rh催化的1,1-二取代的烯丙基醇和胺的高对映选择性的反马尔科夫尼科夫加氢甲酰基化。通过使用手性杂化磷配体,将一系列具有挑战性的1,1-二取代的烯丙醇和胺转化为有价值的手性内酯和内酰胺,具有良好的收率和高对映选择性(高达90%的收率和93%的对映体过量(ee))在非常温和的反应条件下(50°C,CO / H 2 = 2.5 / 2.5 bar)。此外,还实现了克级反应和多种合成转化,证明了该方法的广泛合成效用。
Asymmetric Michael addition of boronic acids to a γ-hydroxy-α,β-unsaturated aldehyde catalyzed by resin-supported peptide
作者:Kengo Akagawa、Masahide Sugiyama、Kazuaki Kudo
DOI:10.1039/c2ob25431j
日期:——
A resin-supportedpeptidecatalyst effective for the asymmetric Michael addition of boronic acids to (E)-4-hydroxybut-2-enal was developed. From a spectral study, it was revealed that the optimum peptide consisted of both a β-turn and helix. Such a combination of secondary structures was essential for achieving a high catalytic ability.
Organocatalytic asymmetric 1,4-addition of organoboronic acids to γ-hydroxy α,β-unsaturated aldehyde: facile synthesis of chiral β-substituted γ-lactones
作者:Sung-Gon Kim
DOI:10.1016/j.tetlet.2008.08.025
日期:2008.10
Catalytic asymmetric 1,4-addition of arylvinyl- and arylboronic acids to a γ-hydroxy α,β-unsaturatedaldehyde, which affords β-substituted γ-lactols, has been established using a diarylprolinol silyl ether as an organocatalyst. The β-substituted γ-lactols have been obtained in good yields and with up to 91% ee, which lead to chiral β-substituted γ-lactones followed by oxidation.