Bis(triphenylphosphine)copper (I) tetrahydroborate in the reduction of -toluenesulphonylhydrazones and 2,4,6-triisopropylbenzenesulphonyl hydrazones (trisyl hdyrazones) to alkanes
Palladium-Catalyzed Cross-Coupling of <i>gem</i>-Bis(boronates) with Aryl Halides: An Alternative To Access Quaternary α-Aryl Aldehydes
作者:Purui Zheng、Yujie Zhai、Xiaoming Zhao、Tao XU
DOI:10.1021/acs.orglett.8b03560
日期:2019.1.18
The compounds with a quaternary α-aryl aldehyde skeleton are important units in organic chemistry. Previously, the aryl group and carbonyl group are introduced in a stepwise manner. Herein, a novel route is developed to construct the quaternary α-aryl aldehydes with gem-bis(boronates) as precursors, in which the two groups are installed simultaneously. The gem-bis(boronates) are readily available from
A matter of catalyst: Azole compounds can be directly alkylated with N‐tosylhydrazones that bear unactivatedalkylgroups (see scheme; phen=1,10‐phenanthroline, Ts=p‐toluenesulfonyl). Nickel catalysis enables the introduction of simple secondary alkyl chains into benzoxazole compounds, whereas the alkylation of 5‐aryloxazoles and benzothiazole is possible by using a cobalt catalyst.
Difunctionalization of ketones <i>via gem</i>-bis(boronates) to synthesize quaternary carbon with high selectivity
作者:Purui Zheng、Yujie Zhai、Xiaoming Zhao、Tao XU
DOI:10.1039/c8cc07781a
日期:——
quaternary centres from ketones via the diborylation process and Suzuki–Miyaura cross-coupling reaction. This methodology, which simultaneously introduces two different kinds of electrophilic structures, exhibits a large substrate scope and high functional group tolerance. The reaction products with aldehyde and allylic groups have proved to be versatile synthons to prepare complex molecules crucial for natural