Hydroxyl-Directed Stereoselective Diboration of Alkenes
作者:Thomas P. Blaisdell、Thomas C. Caya、Liang Zhang、Amparo Sanz-Marco、James P. Morken
DOI:10.1021/ja504228p
日期:2014.7.2
An alkoxide-catalyzed directed diboration of alkenyl alcohols is described. This reaction occurs in a stereoselective fashion and is demonstrated with cyclic and acyclichomoallylic and bishomoallylic alcohol substrates. After oxidation, the reaction generates 1,2-diols such that the process represents a method for the stereoselective directed dihydroxylation of alkenes.
Selective long-distance isomerization of terminal alkenes to silyl enol ethers proceeded via nondissociative chain walking using phenanthroline palladium catalysts. Notable features achieved taking advantage of the nondissociative chain walking mechanism include high efficiency obtained regardless of the chain length, high chemoselectivity toward terminal alkenes over internal ones, and retention of
Striking AcOH Acceleration in Direct Intramolecular Allylic Amination Reactions
作者:Fady Nahra、Frédéric Liron、Guillaume Prestat、Carlo Mealli、Abdelatif Messaoudi、Giovanni Poli
DOI:10.1002/chem.200901946
日期:2009.10.26
An acid–base reaction to speed up a sluggish catalytic cycle! AcOH as the solvent enables extraordinarily fast and efficient PdII‐catalysed, directintramolecularallylicaminations, assisting the benzoquinone‐mediated palladium reoxidation and ionisation of the intermediate palladium complexes (see scheme). The structural and energetic aspects of such a key step of the catalytic cycle are illustrated
An Approach to <i>Lauroxanes</i> by Iterative Use of Co<sub>2</sub>(CO)<sub>6</sub>-Acetylenic Complexes. A Formal Synthesis of (+)-Laurencin
作者:Nuria Ortega、Victor S. Martín、Tomás Martín
DOI:10.1021/jo101566x
日期:2010.10.1
Nicholas reaction to form unsaturated branched linear ethers, a ring closing metathesis to obtain the cobalt complex cyclic ethers, and an isomerization promoted by montmorillonite K-10. A short synthesis of cyclic ethers of seven-, eight-, and nine-memberedrings is described. Additionally, the methodology is exemplified by the formal synthesis of (+)-laurencin, a red algae metabolite.
Enantioselective C(sp<sup>3</sup>)–C(sp<sup>3</sup>) Reductive Cross-Electrophile Coupling of Unactivated Alkyl Halides with α-Chloroboronates via Dual Nickel/Photoredox Catalysis
作者:Jun Zhou、Dong Wang、Wenhao Xu、Zihao Hu、Tao XU
DOI:10.1021/jacs.2c13220
日期:2023.2.1
enantioconvergent C(sp3)–C(sp3) bondformations have been made with nickel-catalyzed cross-coupling of racemic alkyl electrophiles with organometallic reagents or nickel-hydride-catalyzed hydrocarbonation of alkenes. Herein, we report an unprecedented enantioselective C(sp3)–C(sp3) reductive cross-coupling by the direct utilization of two different alkyl halides with dual nickel/photoredoxcatalysis system.