Synthesis of Angiotensin II Receptor Blockers by Means of a Catalytic System for C–H Activation
摘要:
A highly efficient catalytic system for C-H activation has been worked out that involves inexpensive RuCl3.xH(2)O and a specific amount of PPh3. This procedure has been successfully applied to a practical synthesis of angiotensin II receptor blockers (ARBs). The residual ruthenium that existed in the reaction mixture was thoroughly removed by treatment with properly selected metal scavengers. The new process permits ready access to the important class of drugs in a highly atom-economical and sustainable manner.
Late-stage azolation of benzylic C‒H bonds enabled by electrooxidation
作者:Zhixiong Ruan、Zhixing Huang、Zhongnan Xu、Shaogao Zeng、Pengju Feng、Ping-Hua Sun
DOI:10.1007/s11426-020-9938-9
日期:2021.5
The installation of azoles via C-H/N-H cross-coupling is significantly underdeveloped, particularly in benzylic C-H azolation due to the requirement for external chemical oxidants and the challenge in controlling the site- and chemo-selectivity. Herein, a late-stage azolation of benzylic C-H bonds enabled by electrooxidation is described, which proceeds in an undivided cell under mild, catalyst- and
The invention provides a production method of a biaryltetrazole derivative useful as an intermediate for an angiotensin II receptor antagonist. The method comprises reacting an aryltetrazole derivative with a benzene derivative, deprotecting or reducing the resulting compound, and halogenating the deprotected or reduced compound
Transition-Metal-Free Direct Alkylation of Aryl Tetrazoles via Intermolecular Oxidative C–N Formation
作者:Liang Wang、Kaiqiang Zhu、Qun Chen、Mingyang He
DOI:10.1021/jo502283h
日期:2014.12.5
A transition-metal-free synthetic approach for constructing alkylated aryl tetrazoles has been developed using n-Bu4NI as the catalyst and t-BuOOH as the oxidant. It involves the direct C-N bond formation through sp(3) C-H activation. A wide range of benzylic C-H substrates (or alkyl ethers) and aryl tetrazoles undergo this reaction smoothly to deliver the corresponding products in good yields.
Bu<sub>4</sub>NI Catalyzed C–N Bond Formation via Cross-Dehydrogenative Coupling of Aryl Ethers (C<sub>sp3</sub>–H) and Tetrazoles (N–H)
作者:Suresh Rajamanickam、Ganesh Majji、Sourav Kumar Santra、Bhisma K. Patel
DOI:10.1021/acs.orglett.5b02749
日期:2015.11.20
Intermolecular C-N bond formations via cross-dehydrogenative coupling (CDC) of aryl ethers and tetrazoles have been developed under a metal-free condition. In the presence of catalytic amount of tetrabutylammonium iodide (TBAI) and aqueous TBHP, aryl ethers coupled efficiently with tetrazoles to afford hemiaminal ethers. This strategy showed high level of regioselectivity for substrates possessing multiple sp(3) C-H bonds adjacent to the ethereal oxygen.