Synthesis of new chiral keto alcohols by baker’s yeast
作者:Tülay Yıldız、Nurgül Çanta、Ayşe Yusufoğlu
DOI:10.1016/j.tetasy.2014.01.003
日期:2014.2
Fourteen chiral α- and β-keto alcohols 2a–2r were synthesized by the asymmetric reduction of their corresponding diketones 1a–1r viabaker’s yeast. In addition, ten corresponding racemic α-keto alcohols were synthesized by the benzoin condensation of their corresponding aldehydes, which were used for the determination of the ee values through their chiral resolution on chiral HPLC. Amongst the 15 diketones
GO for it! An enantiopure galactoseoxidase (GO) enzyme model has been synthesized from readily available (R)‐binam and Cu(OTf)2 (see scheme; TEMPO=2,2,6,6‐tetramethyl‐piperidin‐1‐oxyl), and has been effectively used as an efficient chiral catalyst for the oxidative kinetic resolution of secondary alcohols. This is the first chiral copper‐catalyzed oxidative kinetic resolution of racemic benzoins and
大胆试试吧!对映纯半乳糖氧化酶(GO)酶模型已从现成的(R)-比纳姆和Cu(OTf)2(参见方案; TEMPO = 2,2,6,6-四甲基-哌啶-1-氧)合成,并且已有效地用作仲醇的氧化动力学拆分的有效手性催化剂。这是外消旋安息香的第一个手性铜催化的氧化动力学拆分,也是合成高度重要的对映体富集的安息香的最简单方法。
Catalytic Asymmetric Acyloin Rearrangements of α-Ketols, α-Hydroxy Aldehydes, and α-Iminols by <i>N</i>,<i>N</i>′-Dioxide–Metal Complexes
N′-dioxide complex as catalyst. This strategy provided an array of optically active 2-acyl-2-hydroxy cyclohexanones in moderate to good yields with high enantioselectivities. The asymmetric isomerizations of acyclic α-hydroxy aldehydes and α-iminols were achieved as well under modified conditions, affording the corresponding chiral α-hydroxy ketones and α-amino ketones in moderate results. Moreover, further
Chiral Frustrated Lewis Pairs Catalyzed Highly Enantioselective Hydrosilylations of 1,2-Dicarbonyl Compounds
作者:Xiaoyu Ren、Haifeng Du
DOI:10.1021/jacs.5b13104
日期:2016.1.27
A highlyenantioselectivehydrosilylation of 1,2-dicarbonyl compounds was successfully realized for the first time utilizing the combination of tricyclohexylphosphine and chiral alkenylborane derived in situ from diyne as a frustrated Lewis pair catalyst. A variety of optically active α-hydroxy ketones and esters were obtained in 52-98% yields with 86-99% ee's.
The first catalyticasymmetric photoreduction of 1,2‐diketones and α‐keto ketimines under visible light irradiation is reported. A transition‐metal‐free synergistic catalysis platform harnessing dicyanopyrazine‐derived chromophore (DPZ) as the photoredox catalyst and a non‐covalent chiral organocatalyst is effective for these transformations. With the flexible use of a chiral Brønsted acid or base in