Catalytic Enantioselective Synthesis of Cyclobutenes from Alkynes and Alkenyl Derivatives
作者:Mahesh M. Parsutkar、Vinayak Vishnu Pagar、T. V. RajanBabu
DOI:10.1021/jacs.9b07885
日期:2019.9.25
compounds from readily available precursors, using scalable and environmentally benign chemistry, can greatly impact their design, synthesis and eventually manufacture on scale. Functionalized cyclobutanes and cyclobutenes are important structural motifs seen in many bioactive natural products and pharmaceutically relevant small molecules. They are also useful precursors for other classes of organic compounds
使用可扩展且环境友好的化学方法,发现用于从容易获得的前体制备手性化合物的对映选择性催化反应,可以极大地影响它们的设计、合成和最终的规模制造。功能化环丁烷和环丁烯是许多生物活性天然产物和药学相关小分子中的重要结构基序。它们也是其他类别有机化合物的有用前体,例如其他环烷烃衍生物、杂环化合物、立体定义的 1,3-二烯和催化不对称合成的配体。制造环丁烯的最简单方法是通过炔烃和烯基衍生物之间的对映选择性 [2+2]-环加成反应,这种反应历史悠久。然而,给出可接受的对映选择性的此类已知反应的范围非常窄,并且严格限于活化的炔烃和高反应性烯烃。在这里,我们公开了一种广泛适用的对映选择性 [2+2]-环加成反应,在各种炔烃和烯基衍生物(两种最丰富的有机前体类别)之间进行。关键的环加成反应使用衍生自易于合成的配体和地球上丰富的金属钴的催化剂。记录了 50 多种对映选择性在 86-97% ee 范围内的不同
Phosphination of Phenol Derivatives and Applications to Divergent Synthesis of Phosphine Ligands
describe a general and efficient protocol for the synthesis of organophosphine compounds from phenols and phosphines (R2PH) via a metal-free C–O bond cleavage and C–P bond formation process. This approach exhibits broad substrate scope and excellent functional group tolerance. The synthetic utilities of this protocol were demonstrated by the synthesis of chiral ligands via the various transformations
A Facile and Modular Synthesis of Phosphinooxazoline Ligands
作者:Kousuke Tani、Douglas C. Behenna、Ryan M. McFadden、Brian M. Stoltz
DOI:10.1021/ol070884s
日期:2007.6.1
iodide catalyzed phosphine/aryl halide coupling procedure of Buchwald et al. provides modular, robust, and scaleable access to phosphinooxazoline (PHOX) ligands. The advantages of this method are highlighted by the convenient synthesis of PHOX ligands with varied steric and electronic properties, which would be challenging to synthesize by other protocols.
Cu/
<scp>Picolinamides‐Catalyzed</scp>
Coupling of (Hetero)aryl Halides with Secondary Phosphine Oxides and Phosphite
<sup>†</sup>
作者:Chao Fang、Bangguo Wei、Dawei Ma
DOI:10.1002/cjoc.202100354
日期:2021.11
Some 4-hydroxy-picolinic acid derived amides were revealed as more efficient ligands for Cu-catalyzed coupling of (hetero)aryl halides with secondary phosphine oxides and phosphites. Only 3—5 mol% CuI and ligands were required to ensure coupling with a number of (hetero)aryl bromides and iodides to complete at 120 oC in 10—20 h.
一些 4-羟基-吡啶甲酸衍生的酰胺被揭示为更有效的配体,用于(杂)芳基卤化物与仲氧化膦和亚磷酸酯的铜催化偶联。仅需要 3-5 mol% CuI 和配体即可确保与许多(杂)芳基溴化物和碘化物的偶联在 120 o C 下在 10-20 小时内完成。
Cobalt-Catalyzed Diastereo- and Enantioselective Reductive Allyl Additions to Aldehydes with Allylic Alcohol Derivatives via Allyl Radical Intermediates
enantioenriched homoallylic alcohols with a remarkably broad scope of allyl groups that can be introduced. Mechanistic studies indicated that allyl radical intermediates were involved in this process. These new discoveries establish a new strategy for development of enantioselective transformations through capture of radicals by chiral Co complexes, pushing forward the frontier of Co complexes for enantioselective