Highly Regioselective Nickel-Catalyzed Cross-Coupling of <i>N</i>-Tosylaziridines and Alkylzinc Reagents
作者:Kim L. Jensen、Eric A. Standley、Timothy F. Jamison
DOI:10.1021/ja505823s
日期:2014.8.6
ligand-controlled, nickel-catalyzed cross-coupling of aliphatic N-tosylaziridines with aliphatic organozinc reagents. The reaction protocol displays complete regioselectivity for reaction at the less hindered C-N bond, and the products are furnished in good to excellent yield for a broad selection of substrates. Moreover, we have developed an air-stablenickel(II) chloride/ligand precatalyst that can be handled and
We describe here a Ni-catalyzed Negishi coupling reaction to prepare 1,2-dialkyl enol ethers in a stereoconvergent fashion. This method employs readily available and bench-stable α-oxy-vinylsulfones as electrophiles. The C–sulfone bond in the α-oxy-vinylsulfone motif is cleaved chemoselectively in these reactions. The mildconditions are tolerant of a variety of functional groups on both partners,
我们在这里描述了一种 Ni 催化的 Negishi 偶联反应,以立体会聚的方式制备 1,2-二烷基烯醇醚。该方法使用容易获得且工作台稳定的 α-氧-乙烯基砜作为亲电试剂。在这些反应中,α-氧-乙烯基砜基序中的 C-砜键被化学选择性地裂解。温和的条件可以容忍双方的各种官能团,因此代表了烯醇醚合成的一般策略。α-氧-乙烯基砜的这种独特的反应性表明它们在交叉偶联反应中作为亲电伙伴的进一步应用。
Directed Nickel-Catalyzed Negishi Cross Coupling of Alkyl Aziridines
作者:Daniel K. Nielsen、Chung-Yang (Dennis) Huang、Abigail G. Doyle
DOI:10.1021/ja4076716
日期:2013.9.11
Herein we report a nickel-catalyzed C-C bond-forming reaction between simple alkyl aziridines and organozinc reagents. This method represents the first catalytic cross-coupling reaction employing a nonallylic and nonbenzylic Csp(3)-N bond as an electrophile. Key to its success is the use of a new N-protecting group (cinsyl or Cn) bearing an electron-deficient olefin that directs oxidative addition
在这里,我们报告了简单的烷基氮丙啶和有机锌试剂之间的镍催化的 CC 键形成反应。这种方法代表了第一个采用非烯丙基和非苄基 Csp(3)-N 键作为亲电子试剂的催化交叉偶联反应。其成功的关键是使用带有缺电子烯烃的新 N 保护基团(cinsyl 或 Cn),该烯烃可指导氧化加成并促进还原消除。还介绍了与阐明交叉耦合机制有关的研究。
Enantio‐ and Regioconvergent Nickel‐Catalyzed C(sp
<sup>3</sup>
)−C(sp
<sup>3</sup>
) Cross‐Coupling of Allylic Electrophiles Steered by a Silyl Group
alkyl-substituted acyclic allylic systems with a stereocenter in the allylicposition is reported. The asymmetric induction and the site selectivity are controlled in an enantio- and regioconvergent nickel-catalyzed C(sp3)−C(sp3) cross-coupling of regioisomeric mixtures of racemic α-/γ-silylated allylic halides and primary alkylzinc reagents. The silylgroup steers the allylic displacement towards the
Enantioconvergent Cross‐Couplings of Alkyl Electrophiles: The Catalytic Asymmetric Synthesis of Organosilanes
作者:Gregg M. Schwarzwalder、Carson D. Matier、Gregory C. Fu
DOI:10.1002/anie.201814208
日期:2019.3.11
Metal-catalyzed enantioconvergent cross-coupling reactions of alkyl electrophiles are emerging as a powerful tool in asymmetricsynthesis. To date, high enantioselectivity has been limited to couplings of electrophiles that bear a directing group or a proximal p/π orbital. Herein, we demonstrate for the first time that enantioconvergent cross-couplings can be achieved with electrophiles that lack such