Tandem Addition β-Lithiation−Alkylation Sequence on α,β-Unsaturated Aldehydes
作者:Norma Sbarbati Nudelman、Graciela V. García
DOI:10.1021/jo005698d
日期:2001.2.1
isotopic exchange reactions and trapping of two intermediates, provide clues on the several mechanistic steps of this new reaction. Extended studies revealed that beta-alkyl-substituted alpha,beta-unsaturated aldehydes and aliphatic lithium reagents did not afford good yields of the tandem reaction products, while aromatic lithium reagents gave good results. The aggregation features of the aryllithium
Enantioselective Conia-Ene-Type Cyclizations of Alkynyl Ketones through Cooperative Action of B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>, <i>N</i>-Alkylamine and a Zn-Based Catalyst
作者:Min Cao、Ahmet Yesilcimen、Masayuki Wasa
DOI:10.1021/jacs.8b13757
日期:2019.3.13
An efficient and highly enantioselective Conia-ene-type process has been developed. Reactions are catalyzed by a combination of B(C6F5)3, an N-alkylamine and a BOX-ZnI2 complex. Specifically, through cooperative action of B(C6F5)3 and amine, ketones with poorly acidic α-C-H bonds can be converted in situ to the corresponding enolates. Subsequent enantioselective cyclization involving a BOX-ZnI2-activated
Racemic tertiary phosphines are obtained from dichlorophenylphosphine by a “one pot” synthesis in two steps: (1) condensation of one equivalent of an organocadmium, and (2) substitution of the second chlorine by another organometallic compound.
A Readily Accessible Class of Chiral Cp Ligands and their Application in Ru
<sup>II</sup>
‐Catalyzed Enantioselective Syntheses of Dihydrobenzoindoles
作者:Shou‐Guo Wang、Sung Hwan Park、Nicolai Cramer
DOI:10.1002/anie.201802244
日期:2018.5.4
Chiral cyclopentadienyl (Cpx) ligands have a large application potential in enantioselective transition‐metal catalysis. However, the development of concise and practical routes to such ligands remains in its infancy. We present a convenient and efficient two‐step synthesis of a novel class of chiral Cpx ligands with tunable steric properties that can be readily used for complexation, giving CpxRhI
手性环戊二烯(Cp x)配体在对映选择性过渡金属催化中具有巨大的应用潜力。但是,开发这种配体的简洁实用的方法仍处于起步阶段。我们提出了一种方便有效的两步合成具有可调空间特性的新型手性Cp x配体的方法,可以很容易地用于络合,得到Cp x Rh I,Cp x Ir I和Cp x Ru II复合体。后者在用炔烃对氮杂苯并降冰片二烯进行对映选择性环化中得到了证明,后者可提供高达98:2 er的二氢苯并吲哚,显着优于现有的由双萘基衍生的Cp x配体。
Novel Building Blocks: 1-Aryl-2-chloro-1-ethoxyethenes – Preparations and Transformations