Streamlined Synthesis of C(sp<sup>3</sup>)-Rich <i>N</i>-Heterospirocycles Enabled by Visible-Light-Mediated Photocatalysis
作者:Nils J. Flodén、Aaron Trowbridge、Darren Willcox、Scarlett M. Walton、Yongjoon Kim、Matthew J. Gaunt
DOI:10.1021/jacs.9b03372
日期:2019.5.29
We report a general visible-light-mediated strategy that enables the construction of complex C(sp3)-rich N-heterospirocycles from feedstock aliphatic ketones and aldehydes with a broad selection of alkene-containing secondary amines. Key to the success of this approach was the utilization of a highly reducing Ir-photocatalyst and orchestration of the intrinsic reactivities of 1,4-cyclohexadiene and
Mild generation of vinylidene carbene from α-amino nitrile is the basis of a new synthesis of homopropargylamines.
从α-氨基腈中产生乙烯基碳烯是合成同异丙炔胺的新方法的基础。
Multifunctional 1,3-diphenylguanidine for the carboxylative cyclization of homopropargyl amines with CO<sub>2</sub> under ambient temperature and pressure
could be utilized for the carboxylative cyclization of homopropargyl amines with CO2 under ambient temperature and pressure, in combination with AgSbF6, which enabled the synthesis of both chiral and achiral 2-oxazinones efficiently. A mechanistic study revealed that the multi-functionality of DPG is critical to the success of the reaction.
CATALYTIC SYSTEMS FOR STEREOSELECTIVE SYNTHESIS OF CHIRAL AMINES BY ENANTIODIVERGENT RADICAL C-H AMINATION
申请人:Trustees of Boston College
公开号:US20200317627A1
公开(公告)日:2020-10-08
In one aspect, the disclosure relates to a mode of asymmetric induction in radical processes based on sequential combination of enantiodifferentiative H-atom abstraction and stereoretentive radical substitution. Also disclosed is an asymmetric system for stereoselective synthesis of strained 5-membered cyclic sulfamides via radical 1,5-C—H amination of sulfamoyl azides. The disclosed metalloradical system can control the degree and sense of asymmetric induction in the catalytic radical C—H amination in a systematic manner. The disclosed system is applicable to a broad scope of substrates with different types of C(sp
3
)-H bonds and exhibits reactivity and selectivity, providing access to both enantiomers of useful 5-membered cyclic sulfamides in a highly enantioenriched form. Also disclosed are catalysts useful in these processes. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.
The first asymmetric total synthesis of (+)-flabellidine (2) and the shortest total synthesis of (-)-lycodine (3) were accomplished by a strategy featuring the one-pot construction of a tetracyclic lycodine skeleton from a linear precursor, which was inspired by the biosynthetic consideration of Lycopodium alkaloids.