principle of electrochemical oxidation of aryl rings has been utilized to relieve the strain of donor-acceptor cyclopropane and further trap the molecular oxygen to deliver the 1,3-bifunctionalized product. Hence, the methodology bestows a novel route towards the scalable synthesis of β-hydroxy ketones.
Asymmetric Ring-Opening of Donor–Acceptor Cyclopropanes with Primary Arylamines Catalyzed by a Chiral Heterobimetallic Catalyst
作者:Weiwei Luo、Zhicheng Sun、E. H. Nisala Fernando、Vladimir N. Nesterov、Thomas R. Cundari、Hong Wang
DOI:10.1021/acscatal.9b02523
日期:2019.9.6
asymmetric ring-opening reaction of donor–acceptor cyclopropanes with primary arylamines was developed. The reaction was achieved through the utilization of a chiral heterobimetallic catalyst, delivering a variety of chiral γ-amino acid derivatives in up to 93% yield and 99% ee. Stereochemical experiments suggest a dominant role for kinetic resolution in this asymmetric process, which is supported by
开发了供体-受体环丙烷与伯芳基胺的有效催化不对称开环反应。该反应是通过利用手性杂双金属催化剂实现的,以高达93%的收率和99%的ee提供了各种手性的γ-氨基酸衍生物。立体化学实验表明,在该不对称过程中动力学拆分起着主导作用,这一点得到了对反应坐标的计算研究的支持。在这项工作中介绍了通过配体交换/重金属化过程形成的一类手性双金属路易斯酸催化剂。X射线晶体学证实了双金属催化剂的对称结构,即Yb(OTf)3 -Yb [ P ] 3。
AlCl<sub>3</sub>-Promoted Formal [2 + 3]-Cycloaddition of 1,1-Cyclopropane Diesters with <i>N</i>-Benzylic Sulfonamides To Construct Highly Stereoselective Indane Derivatives
作者:Mengyun Zhu、Jinqian Liu、Jianjun Yu、Liangshun Chen、Chunmei Zhang、Limin Wang
DOI:10.1021/ol500136x
日期:2014.4.4
An unprecedented AlCl3-promoted formal [2 + 3]-cycloaddition of 1,1-cyclopropanes with readily available N-benzylic sulfonamides has been developed. Experimental evidence supports an unusual mechanism wherein the donor acceptor cyclopropane serves as a source of 2-styrylmalonate rather than the "classical" 1,3-dipole. A broad range of 1,1-cyclopropanediesters undergo a carbocation-initiated cyclization reaction with N-benzylic sulfonamides to afford highly functionalized Indane derivatives in a fast and high-yielding procedure.
Divergent Copper‐salt‐controlled Reactions of Donor‐Acceptor Cyclopropanes and
<i>N</i>
‐Fluorobenzene Sulfonimide: Access to the 1,3‐Haloamines and Aminoindanes
作者:Lingyan Liu、Xiao Wang、Weiguo Xiao、Weixing Chang、Jing Li
DOI:10.1002/chem.202202544
日期:2023.1.12
AbstractWe herein report a method for divergent copper salt controlled reactions of donor‐acceptor cyclopropanes and N‐fluorobenzene sulfonimide (NFSI). Specifically, in the presence of CuX2 (X=Cl, Br), the cyclopropanes underwent formal umpolung 1,3‐aminohalogenation bifunctionalization via a free radical mediated ring‐opening process to afford 1,3‐aminochlorination and 1,3‐aminobromination products in moderate to good yields. In addition, by using CuI as a catalyst, we synthesized various aminoindane derivatives via 1,3‐aminoarylation cyclization of D‐A cyclopropanes, the reactions involved a free radical mediated ring‐opening and subsequent ring expansion via C−H bond activation.