From Mono-Triazolium Salt to Bis-Triazolium Salt: Improvement of the Asymmetric Intermolecular Benzoin Condensation
作者:Yajun Ma、Siping Wei、Jie Wu、Fei Yang、Bo Liu、Jingbo Lan、Shengyong Yang、Jingsong You
DOI:10.1002/adsc.200800371
日期:2008.11.3
method for the enantioselective intermolecular benzoincondensation of aromatic aldehydes is described. The chiral bis-bicyclic triazolium salt – 1,3-bis(S)-5-benzyl-6,8-dihydro-5H-[1,4]oxazino[2,1-c][1,2,4]triazol-2-ium-2-yl}benzene dichloride [(S)-5a-1] is currently the most efficient precatalyst for the asymmetric variant of the benzoincondensation.
描述了解决开发高效率的方法用于芳族醛的对映选择性分子间安息香缩合的长期挑战的解决方案。手性双-双环三唑鎓盐– 1,3-双(S)-5-苄基-6,8-二氢-5 H- [1,4]恶嗪[2,1- c ] [1,2,4 ]三唑-2-鎓-2-基}苯二氯化物[(S)-5a-1 ]目前是用于安息香缩合反应的不对称变体的最有效的预催化剂。
Galactose Oxidase Model: Biomimetic Enantiomer-Differentiating Oxidation of Alcohols by a Chiral Copper Complex
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。
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.
Base-Free Asymmetric Transfer Hydrogenation of 1,2-Di- and Monoketones Catalyzed by a (NH)<sub>2</sub>
P<sub>2</sub>
-Macrocyclic Iron(II) Hydride
作者:Lorena De Luca、Antonio Mezzetti
DOI:10.1002/anie.201706261
日期:2017.9.18
Base? No thanks! A hydride isonitrile iron(II) complex bearing a C2-symmetric diamino (NH)2P2 macrocyclic ligand catalyzes the asymmetric transferhydrogenation of ketones under base-free conditions with excellent enantioselectivity (up to 99 % ee). Base-labile benzoins are formed from the corresponding benzils with up to 95 % ee.
根据?不用了,谢谢!带有C 2对称二氨基(NH)2 P 2大环配体的氢化物异腈铁(II)络合物在无碱条件下催化酮的不对称转移氢化,具有出色的对映选择性(最高99%ee)。碱不稳定的安息香由相应的苯构成,其ee最高可达95%。
Biocatalyzed asymmetric reduction of benzils to either benzoins or hydrobenzoins: pH dependent switch
作者:Mohan Pal、Gautam Srivastava、Amar Nath Sharma、Suneet Kaur、Ravinder S. Jolly
DOI:10.1039/c5cy00158g
日期:——
synthesis. Biocatalytic reduction of benzils is a straightforward approach to prepare these molecules. However, known methods are not selective and lead to formation of a mixture of benzoin and hydrobenzoin, requiring expensive separation procedures. Here, we describe an enzyme system Talaromyces flavus, which exhibited excellent pH dependent selectivity for the conversion of benzil to either benzoin or