Preparation of Solid, Substituted Allylic Zinc Reagents and Their Reactions with Electrophiles
作者:Mario Ellwart、Paul Knochel
DOI:10.1002/anie.201504354
日期:2015.9.1
The treatment of various allylic chlorides or bromides with zinc dust in the presence of lithiumchloride and magnesium pivalate (Mg(OCOtBu)2) in THF affords allylic zinc reagents which, after evaporation of the solvent, produce solid zinc reagents that display excellent thermal stability. These allylic reagents undergo Pd‐catalyzed cross‐coupling reactions with PEPPSI‐IPent, as well as highly regioselective
在氯化锂和新戊酸镁(Mg(OCO t Bu)2)在THF中存在的情况下,用锌粉处理各种烯丙基氯化物或溴化物,可得到烯丙基锌试剂,该溶剂蒸发后,生成的固态锌试剂显示出优异的热稳定性。这些烯丙基试剂与PEPPSI-IPent进行Pd催化的交叉偶联反应,以及对芳基酮和醛进行高度区域选择性和非对映选择性的加成。酰化与各种酰氯区域选择性地产生相应的高烯丙基酮,用新的C C键总是被形成在烯丙基系统的最受阻碳。
Palladium-catalyzed prenylation of (hetero)aryl boronic acids
作者:Jeffrey Leister、Darrian Chao、Kelvin L. Billingsley
DOI:10.1016/j.tetlet.2020.152800
日期:2021.3
cross-coupling of aryl and heteroaryl boronicacids with prenyl alcohol. Catalyst systems based on dialkylbiaryl phosphines were highly active for this transformation. These supporting ligands provided opportunities for tuning the efficiency and regioselectivity of carbon–carbon bond formation. In addition, this method was further extended to the cross-coupling of symmetrical allylic alcohols with aryl boronic
[EN] ORGANOZINC REAGENTS AND PROCESSES FOR PREPARING AND USING THE SAME<br/>[FR] RÉACTIFS ORGANOZINCIQUES ET LEURS PROCÉDÉS DE PRÉPARATION ET D'UTILISATION
申请人:UNIV MUENCHEN LUDWIG MAXIMILIANS
公开号:WO2016146689A1
公开(公告)日:2016-09-22
Provided is an organozinc composition comprising (a) an organozinc complex carrying an allylic ligand, (b) a magnesium component and (c) a lithium component. The organozinc composition is useful as a synthetic intermediate with excellent reactivity and selectivity, and can be stored for extended periods of time without loss of activity. Moreover, a process for the preparation of the organozinc composition and synthetic procedures making use of the organozinc composition are provided.
Regioselective Cross-Coupling of Allylboronic Acid Pinacol Ester Derivatives with Aryl Halides via <i>Pd-PEPPSI-IPent</i>
作者:Jennifer L. Farmer、Howard N. Hunter、Michael G. Organ
DOI:10.1021/ja308613b
日期:2012.10.24
The cross-coupling reactions of allylboronic acid pinacol ester derivatives with aryl and heteroaryl halides occurred with high selectivity (>97%) at the α-carbon of the allylboron reagent in the presence of Pd-PEPPSI-IPent precatalyst and 5 M KOH in refluxing THF. In the case of trisubstituted allylboronates with different substituents on the olefin, minor olefin geometry isomerization was observed
An efficient dehydrogenative Diels–Alderreaction of prenyl derivatives with dienophiles has been developed. The reaction exhibits broad substrate scope and provides efficient access to cyclohexene derivatives with good to excellent yields. A reasonable mechanism involving a metal-free thermal reversible process is proposed.