Metal-Free and Redox-Neutral Conversion of Organotrifluoroborates into Radicals Enabled by Visible Light
作者:Wenbo Liu、Peng Liu、Leiyang Lv、Chao-Jun Li
DOI:10.1002/anie.201807181
日期:2018.10.8
through an SH2 process. This strategy is enabled by using water as the solvent, visible light as the energy input, and diacetyl as the promoter in the absence of any metal catalyst or redox reagent, thereby eliminating metal waste. To demonstrate its synthetic utility, an efficient acetylation to prepare valuable aryl (alkyl) methyl ketones is described and applications to construct C−C, C−I, C−Br
将有机硼化合物转化为相应的基团在有机化学中具有广泛的合成应用。为了实现这些转化,需要采用化学计量的各种强氧化剂如Mn(OAc)3,AgNO 3 / K 2 S 2 O 8和Cu(OAc)2,并通过单电子转移机理进行。本文确立了一种独特的策略,可通过S H从有机三氟硼酸盐生成芳基和烷基2过程。在没有任何金属催化剂或氧化还原试剂的情况下,通过使用水作为溶剂,使用可见光作为能量输入,使用二乙酰作为促进剂来启用此策略,从而消除了金属浪费。为了证明其合成用途,描述了一种有效的乙酰化反应以制备有价值的芳基(烷基)甲基酮,并且构造C-C,C-I,C-Br和C-S键的应用也是可行的。实验证据表明,三联体二乙酰是该过程的关键中间体。
Brønsted Acid-Catalyzed Reactions of Trifluoroborate Salts with Benzhydryl Alcohols
作者:Kayla M. Fisher、Yuri Bolshan
DOI:10.1021/acs.joc.5b02273
日期:2015.12.18
alkenyltrifluoroborate salts has been developed. Organotrifluoroborates react with benzhydryl alcohols to afford a broad range of alkynes and alkenes in good to excellent yields. This protocol features good atom economy because organotrifluoroboratesalts and alcohols react in a 1:1 ratio. Furthermore, a variety of unprotected functional groups were tolerated under the developed conditions, including amide
A General Access to Propargylic Ethers through Brønsted Acid Catalyzed Alkynylation of Acetals and Ketals with Trifluoroborates
作者:Matthew Baxter、Yuri Bolshan
DOI:10.1002/chem.201502797
日期:2015.9.21
A general Brønsted acid catalyzed methodology for the alkynylation of acetals and ketals with alkynyltrifluoroborate salts has been developed. The reaction proceeds rapidly to afford valuable synthetic building block propargylic ethers in good to excellent yields. Unlike Lewis acid catalyzed transformations of trifluoroborates, this approach does not proceed via unstable organodifluoroborane intermediate
Direct oxidative C–H alkynylation of <i>N</i>-carbamoyl tetrahydroisoquinolines and dihydroisoquinolines
作者:Lei Chen、Chuanxi Sun、Guidong Feng、Min Cao、Shu-lei Zhao、Jun Yan、Ren-zhong Wan、Lei Liu
DOI:10.1039/c8ob00373d
日期:——
An efficient oxidative C–H alkynylation of N-carbamoyl tetrahydroisoquinolines mediated by a TEMPO oxoammonium salt has been established. A variety of electronically varied N-carbamoyl tetrahydroisoquinolines reacted with a range of alkynyl potassium trifluoroborates smoothly under mild metal-free conditions. Dihydroisoquinolines were also suitable components for the reaction. The synthetic applicability
Three-component reaction for the synthesis of diverse β-unsaturated α-amino esters
作者:Hélio A. Stefani、Flávia Manarin、Ariane C.S. Sousa、Frederico B. Souza、Witor Ribeiro Ferraz
DOI:10.1016/j.tet.2013.11.107
日期:2014.5
We describe an efficient multicomponent reaction for the preparation of β-unsaturatedα-aminoesters by ytterbium triflate catalyzed reaction of potassium organotrifluoroborate salts, aniline and ethyl glyoxalate. The synthetic viability of this protocol was demonstrated by moderate to high yields, short reaction time ranging from 0.5 to 12 h, and efficiency with respect to substrate scope.