Directaminations of allylic alcohols, benzylic alcohols, and benzhydrols with electron‐withdrawing (F, Br, I, NO2, or CN) substituents were efficiently catalyzed by aluminumtriflate [Al(OTf)3] to afford the corresponding biarylamines in high yield, and the dibromo‐substituted product was further transformed into letrozole.
Chiral oxime ethers in asymmetric synthesis. Part 5.1 Asymmetric synthesis of 2-substituted 5- to 8-membered nitrogen heterocycles by oxime addition–ring-closing metathesis
作者:James C. A. Hunt、Pierre Laurent、Christopher J. Moody
DOI:10.1039/b207235c
日期:——
Addition of organometallic reagents to chiral oxime ethers 1 derived from an unsaturated aldehyde, or addition of an alkene containing organometallic to chiral aldoxime ethers 2 results in highly stereoselective formation of the hydroxylamines 6. N-Allylation gives the dienes 7 which undergo ring-closingmetathesis (RCM) reaction to give the 5-, 6-, and 7-membered nitrogen heterocycles 8. Likewise
The first example of simple Re2O7-catalyzed direct dehydrative coupling between allylic alcohols with electron-deficient amines has been achieved under mild and open flask conditions. The protocol has also been successfully applied to benzylic and propargylic alcohols. The mechanistic proof for the SN1-type process has also been provided.
在温和和开放的烧瓶条件下,已经实现了烯丙基醇与缺电子的胺之间简单的Re 2 O 7催化的直接脱水偶合的第一个例子。该协议也已成功应用于苄醇和炔丙基醇。还提供了用于S N 1型过程的机理证明。
Gold(I)-Catalyzed Stereoconvergent, Intermolecular Enantioselective Hydroamination of Allenes
作者:Kristina L. Butler、Michele Tragni、Ross A. Widenhoefer
DOI:10.1002/anie.201201584
日期:2012.5.21
Gold and silver: A 1:2 mixture of [(S)‐1}(AuCl)2] and AgBF4 catalyzes the enantioselectivehydroamination of chiral, racemic 1,3‐disubstituted allenes with N‐unsubstituted carbamates to form N‐allylic carbamates in good yield, with high regio‐ and diastereoselectivity, and up to 92 % ee (see scheme, Cbz=benzyloxycarbonyl).
Intermolecular Hydroamination of Allenes with <i>N</i>-Unsubstituted Carbamates Catalyzed by a Gold(I) <i>N</i>-Heterocyclic Carbene Complex
作者:Robert E. Kinder、Zhibin Zhang、Ross A. Widenhoefer
DOI:10.1021/ol8010858
日期:2008.7.17
Reaction of 2,3-pentadienyl benzoate with benzyl carbamate catalyzed by a 1:1 mixture of (NHC)AuCl and AgOTf in dioxane at 23 degrees C for 5 h led to isolation of (E)-4-(benzyloxycarbonylamino)-2-pentenyl benzoate in 84% yield as a single regio- and diastereomer. Gold(I)-catalyzed hydroamination was effective for a number of N-unsubstituted carbamates and a range of substituted allenes.