Aminopalladation-Triggered Carbene Insertion Reaction: Synthesis of 2-(1<i>H</i>-Indol-3-yl)acetates
作者:Ziwei Hu、Shuang Luo、Qiang Zhu
DOI:10.1002/adsc.201400799
日期:2015.3.23
red carbeneinsertionreaction for the synthesis of C‐3 alkylated indole derivatives from ortho‐alkynyltrifluoroacetanilides and α‐diazoacetates is presented; it involves a palladium catalyst and a weak base in the open air. Yields range from 49–88% with excellent functional group tolerance. The reaction proceeds through intramolecular aminopalladation of alkynes followed by carbeneinsertion. Migratory
Copper-catalyzed N–H insertion reactions from sulfoxonium ylides
作者:Lucas G. Furniel、Antonio C.B. Burtoloso
DOI:10.1016/j.tet.2020.131313
日期:2020.12
The first use of copper(II) as an efficient catalyst for N–H insertionreactions between anilines and α-carbonyl sulfoxoniumylides is described. Products, 39 arylglycine derivatives, were obtained in yields up to 97% employing a simple and fast experimental procedure.
Herein, a donor/acceptor-free carbene insertionreaction of an S–S bond through a radical process is presented. This catalyst-free reaction was thermally induced and provided the dithioketal products in moderate to high yields. A mechanism involving radical intermediates was proposed according to the computationalstudy, and these intermediates were verified experimentally and intercepted for the first
Catalytic Enantio- and Diastereoselective Cyclopropanation of 2-Azadienes for the Synthesis of Aminocyclopropanes Bearing Quaternary Carbon Stereogenic Centers
作者:Xinxin Shao、Steven J. Malcolmson
DOI:10.1021/acs.orglett.9b02692
日期:2019.9.20
We report the catalyticenantio- and diastereoselective preparation of aminocyclopropanes by the cyclopropanation of terminal and (Z)-internal 2-azadienes with donor/acceptor carbenes derived from α-diazoesters. The resulting cyclopropanes bear quaternary carbon stereogenic centers vicinal to the amino-substituted carbon and are formed as a single diastereomer in up to 99:1 er and 97% yield with 0
我们报道了通过末端和( Z )-内部2-氮杂二烯与源自α-重氮酯的供体/受体卡宾的环丙烷化,催化对映和非对映选择性制备氨基环丙烷。所得环丙烷带有与氨基取代碳相邻的季碳立构中心,并以高达 99:1 er 和 97% 产率形成单一非对映异构体,其中使用 0.5 mol% 的 Rh 2 (DOSP) 4 和仅1.5当量的重氮试剂。内部氮杂二烯的转化提供了具有三个连续立体中心的环丙烷。
Diastereoselective Trapping of Transient Carboxylic Oxonium Ylides with α,β‐Unsaturated 2‐Acyl Imidazoles
作者:Mengchu Zhang、Tianyuan Zhang、Dan Zhang、Wenhao Hu
DOI:10.1002/adsc.202000701
日期:2020.11.4
By developing a diastereoselective reaction of cyclopropene carboxylic acids with α,β‐unsaturated 2‐acylimidazoles, we reported here a Michael‐type trapping of transient carboxylic oxonium ylides. This transformation provides a direct approach for the construction of valuable γ‐butenolide derivatives in good yields (60–99%) with high diastereoselectivities (up to >95:5 dr) under mild reaction conditions