Microbial hydroxylation of 2-cycloalkylbenzoxazoles. Part I. Product spectrum obtained from Cunninghamella blakesleeana DSM 1906 and Bacillus megaterium DSM 32
摘要:
2-Cycloalkyl-1, 3-benzoxazoles and -thiazoles (ring sizes C-3 to C-8) were biotransformed using the title microorganisms. Products of preparative importance were (1S, 3S)-3-(benz-1, 3-oxazol-2-yl)cyclopentan-1-ol 6, (1R)-3-(benz-1, 3-oxazol-2-yl)cyclopentan-1-one 8, (1R, 2R)-2-(benz-1, 3-oxazol-2-yl)cyclohexan-1-ol 14 and the corresponding cycloheptanol and cycloheptanone derivatives.
Mn(II)-Catalyzed C–H Alkylation of Imidazopyridines and <i>N</i>-Heteroarenes via Decarbonylative and Cross-Dehydrogenative Coupling
作者:Sadhanendu Samanta、Alakananda Hajra
DOI:10.1021/acs.joc.9b00366
日期:2019.4.5
A Mn(II)-catalyzed efficient C–H alkylation of imidazoheterocycles and N-heteroarenes with aliphatic aldehydes has been developed via oxidative decarbonylation. Other alkylating agents such as cyclic alkanes, ethers, and alcohols also coupled with N-heteroarenes through cross-dehydrogenative coupling. Regioselectively C5-alkylated imidazoheterocycles were synthesized in good yields. Experimental results
Introduction of Heteroaromatic Bases onto Cycloalkanes with BPO
作者:Luan Zhou、Hideo Togo
DOI:10.1002/ejoc.201801797
日期:2019.2.21
Treatment of heteroaromatics with BPO and CF3CO2H in cycloalkanes at 100 °C for 4 h generated C–C bonded heteroaromaticbases bearing cycloaklyl group in good yields under transition‐metal‐free conditions.
在环烷烃中,用BPO和CF 3 CO 2 H在100°C下处理杂芳族化合物4小时,在无过渡金属的条件下,生成的具有C-C键合的带有环烯丙基的杂芳族碱的收率很高。
Photoelectrochemical cross-dehydrogenative coupling of benzothiazoles with strong aliphatic C–H bonds
作者:Luca Capaldo、Lorenzo L. Quadri、Daniele Merli、Davide Ravelli
DOI:10.1039/d1cc01012c
日期:——
cross-dehydrogenative coupling of unactivated aliphatic hydrogen donors (e.g. alkanes) with benzothiazoles is reported. We used tetrabutylammonium decatungstate as the photocatalyst to activate strong C(sp3)–H bonds in the chosen substrates, while electrochemistry scavenged the extra electrons.
Desulfonative photoredox alkylation of <i>N</i>-heteroaryl sulfones – an acid-free approach for substituted heteroarene synthesis
作者:Zheng-Jun Wang、Shuai Zheng、Jennifer K. Matsui、Zhipeng Lu、Gary A. Molander
DOI:10.1039/c9sc00776h
日期:——
Minisci-type alkylation of electron-deficient heteroarenes has been a pivotal technique for medicinal chemists in the synthesis of drug-like molecules. However, such transformations usually require harsh conditions (e.g., strong acids, stoichiometric amount of oxidants, elevated temperatures, etc.). Herein, by utilizing photoredoxcatalysis, a highly-selective alkylation method using heteroaryl sulfones
Photoredox-Mediated Direct Cross-Dehydrogenative Coupling of Heteroarenes and Amines
作者:Jianyang Dong、Qing Xia、Xueli Lv、Changcun Yan、Hongjian Song、Yuxiu Liu、Qingmin Wang
DOI:10.1021/acs.orglett.8b02389
日期:2018.9.21
A photoredox-mediated direct cross-dehydrogenativecouplingreaction to accomplish α-aminoalkylation of N-heteroarenes is reported. This mild reaction has a broad substrate scope, offers the first general method for synthesis of aminoalkylated N-heteroarenes without the need for substrate prefunctionalization, and is scalable to the gram level. Furthermore, the reaction was found to be applicable to