在此,我们报告的环酮酯和酰胺的电炔基随着研究的深入ê thynyl b enziodo X olone(EBX)试剂。首先更详细地描述这类试剂的结构和稳定性。差示扫描量热法(DSC)实验表明,使用EBX试剂会发生强烈的放热分解,从而为安全使用这些化合物提供了指导。然后报道了将该方法扩展到芳族炔烃和广泛的苯并齐多酚(on)e试剂。根据我们使用Cinchona的初步结果基于相转移催化剂,可以实现环酮酯的对映选择性炔基化。由Maruoka和他的同事开发的由联萘胺衍生的铵催化剂提供了最高的不对称诱导率,对于茚满酮衍生的酮酯,ee高达79%。在整个工作过程中,仅在苯并恶唑酮试剂中观察到不对称诱导,证明了它们优于常规烷基炔诺酮盐。对导致更高的不对称诱导的因素的更深入的了解将在将来开发一种真正通用的和高度对映选择性的炔基化方法中非常有用。
Enantioselective Copper-Catalyzed Oxy-Alkynylation of Diazo Compounds
作者:Durga Prasad Hari、Jerome Waser
DOI:10.1021/jacs.7b04756
日期:2017.6.28
Enantioselective catalytic methods allowing the addition of both a nucleophile and an electrophile onto diazocompounds give a fast access into important building blocks. Herein, we report the highly enantioselective oxyalkynylation of diazocompounds using ethynylbenziodoxol-(on)e reagents and a simple copper bisoxazoline catalyst. The obtained α-benzoyloxy propargylic esters are useful building blocks
copper(I)-catalyzed vinylation of diazo compounds with vinylbenziodoxolone reagents (VBX) as partners is reported. The transformation tolerates diversefunctionalities on both reagents delivering polyfunctionalized vinylated products. The strategy was successfully extended to a three-component/intermolecular version with alcohols. The obtained products contain synthetically versatile functional groups, such
A novel regio‐ and diastereoselective iron‐catalyzed intermolecular oxyazidation of enamidesusing various azidobenziodoxolone (ABX) derivatives is presented. A variety of α‐N3 amino derivatives and of α‐N3 piperidines were synthesized in good yields and under mild reaction conditions. The reaction involves a radical process using cheap FeCl2 as the initiator.
Copper-Catalyzed Oxy-Alkynylation of Diazo Compounds with Hypervalent Iodine Reagents
作者:Durga Prasad Hari、Jerome Waser
DOI:10.1021/jacs.6b00278
日期:2016.2.24
Alkynes have found widespread applications in synthetic chemistry, biology, and materials sciences. In recent years, methods based on electrophilic alkynylation with hypervalent iodine reagents have made acetylene synthesis more flexible and efficient, but they lead to the formation of one equivalent of an iodoarene as side-product. Herein, a more efficient strategy involving a copper-catalyzed oxy-alkynylation
Selective Carbonyl−C(sp<sup>3</sup>) Bond Cleavage To Construct Ynamides, Ynoates, and Ynones by Photoredox Catalysis
作者:Kunfang Jia、Yue Pan、Yiyun Chen
DOI:10.1002/anie.201611897
日期:2017.2.20
Carbon–carbonbondcleavage/functionalization is synthetically valuable, and selective carbonyl−C(sp3) bondcleavage/alkynylation presents a new perspective in constructing ynamides, ynoates, and ynones. Reported here is the first alkoxyl‐radical‐enabled carbonyl−C(sp3) bondcleavage/alkynylation reaction by photoredox catalysis. The use of novel cyclic iodine(III) reagents are essential for β‐carbonyl