Ring Opening of Donor-Acceptor Cyclopropanes with the Azide Ion: A Tool for Construction of N-Heterocycles
作者:Konstantin L. Ivanov、Elena V. Villemson、Ekaterina M. Budynina、Olga A. Ivanova、Igor V. Trushkov、Mikhail Ya. Melnikov
DOI:10.1002/chem.201405551
日期:2015.3.23
general method for ringopening of various donor–acceptor cyclopropanes with the azide ion through an SN2‐like reaction has been developed. This highly regioselective and stereospecific process proceeds through nucleophilic attack on the more‐substituted C2 atom of a cyclopropane with complete inversion of configuration at this center. Results of DFT calculations support the SN2 mechanism and demonstrate
已经开发出一种通用的方法,可通过类似S N 2的反应,将叠氮离子与各种供体-受体环丙烷开环。这种高度区域选择性和立体选择性的过程是通过亲核攻击环丙烷的更取代的C2原子进行的,该中心的构型完全反转。DFT计算结果支持S N2机理,证明环丙烷的相对实验反应性与计算出的能垒之间具有良好的定性相关性。该反应为多种多官能叠氮化物提供了一种简单的方法,产率高达91%。这些叠氮化物具有很高的合成效用,并参与了面向多样性的合成,这是通过已开发的将其转变为五元,六元和七元N杂环以及复杂的环状化合物的多径策略证明的。包括天然产物和药物,如(-)-尼古丁和阿托伐他汀。
Tertiary and Quaternary Carbon Formation via Gallium-Catalyzed Nucleophilic Addition of Organoboronates to Cyclopropanes
作者:Truong N. Nguyen、Jeremy A. May
DOI:10.1021/acs.orglett.7b03349
日期:2018.1.5
via homoconjugate addition of organoboron nucleophiles to diester- and ketone-functionalized cyclopropanes. Electron donor group cyclopropane substituents were not needed, allowing electron-deficient aryl, alkenyl, alkyl, and hydrogen-substituted cyclopropanes to be used. The catalytic conditions were compatible with alkenyl, alkynyl, and arylnucleophiles, including ortho-substituted aromatics, to
Electrocatalytic Activation of Donor–Acceptor Cyclopropanes and Cyclobutanes: An Alternative C(sp
<sup>3</sup>
)−C(sp
<sup>3</sup>
) Cleavage Mode
作者:Simon Kolb、Martin Petzold、Felix Brandt、Peter G. Jones、Christoph R. Jacob、Daniel B. Werz
DOI:10.1002/anie.202101477
日期:2021.7.12
We describe the first electrochemical activation of D–A cyclopropanes and D–A cyclobutanes leading after C(sp3)−C(sp3) cleavage to the formation of highly reactive radical cations. This concept is utilized to formally insert molecular oxygen after direct or DDQ-assisted anodic oxidation of the strained carbocycles, delivering β- and γ-hydroxy ketones and 1,2-dioxanes electrocatalytically. Furthermore
Regioselective Hydrogenolysis of Donor–Acceptor Cyclopropanes with Zn-AcOH Reductive System
作者:Konstantin L. Ivanov、Elena V. Villemson、Gennadij V. Latyshev、Stanislav I. Bezzubov、Alexander G. Majouga、Mikhail Ya. Melnikov、Ekaterina M. Budynina
DOI:10.1021/acs.joc.7b01549
日期:2017.9.15
convenient low-cost method for regioselective ring-opening of donor–acceptor cyclopropanes with the Zn-AcOH reductive system was developed. The general character of the method was displayed via efficient reduction of a representative series of 2-(het)arylcyclopropane-1,1-diesters as well as donor–acceptor cyclopropanes with other types of electron-withdrawing activating groups. This method opens a rapid
RhII-Catalyzed Thermal Cyclopropanations of a Phenyliodonium Bis(carbomethoxy)methylide with Alkenes and Dienes
作者:Georgia Georgakopoulou、Christos Kalogiros、Lazaros P. Hadjiarapoglou
DOI:10.1055/s-2001-18750
日期:——
Iodonium ylide 2, derived from dimethyl malonate, undergoes facile thermal cycloaddition with alkenes and dienes catalyzed with Rh2(OAc)4 to form the corresponding cyclopropanedicarboxylates and vinylcyclopropanedicarboxylates, respectively, in excellent yields.