Visible Light-Induced Selective Generation of Radicals from Organoborates by Photoredox Catalysis
作者:Yusuke Yasu、Takashi Koike、Munetaka Akita
DOI:10.1002/adsc.201200588
日期:2012.12.14
A new strategy for the generation of carbon-centered radicals via oxidation of alkyl-, allyl-, benzyl- and arylborates by visible-light-driven single electron transfer (SET) photoredoxcatalysis has been established. The generated radicals smoothly react with TEMPO and electron-deficient alkenes to afford CO and CC coupling products, respectively. In this radical initiating system, cyclic organo(triol)borates
An efficient protocol for the synthesis of alpha-benzyl azetidines starting from benzylboronic acid pinacol ester derivatives and 3-iodoazetidine was developed. A wide range of alpha-benzyl azetidine derivatives were obtained in moderate to good yields with high regioselectivity (>99%). (C) 2019 Elsevier Ltd. All rights reserved.
SYNTHESIS OF BENZYLBORONATES VIA PALLADIUM-CATALYZED BORYLATION OF BENZYL HALIDES WITH PINACOLBORANE
Various benzyl halides were borylated with pinacolborane in the presence of (Pr2NEt)-Pr-i and a catalytic amount of PdCl2(PPh3)(2) to afford the corresponding benzylboronates in good yields.
Photochemical Radical C–H Halogenation of Benzyl N‐Methyliminodiacetyl (MIDA) Boronates: Synthesis of α‐Functionalized Alkyl Boronates
作者:Ling Yang、Dong‐Hang Tan、Wen‐Xin Fan、Xu‐Ge Liu、Jia‐Qiang Wu、Zhi‐Shu Huang、Qingjiang Li、Honggen Wang
DOI:10.1002/anie.202011872
日期:2021.2.15
α‐haloboronates are limiting and often suffer from harsh reaction conditions. Reported herein is a photochemical radical C‐H halogenation of benzyl N‐methyliminodiacetyl (MIDA) boronates. Fluorination, chlorination, and bromination reactions were effective by using this protocol. Upon reaction with different nucleophiles, the C−Br bond in the brominated product could be readily transformed to a series of C−C