Tandem Ring-Closing Metathesis/Transfer Hydrogenation: Practical Chemoselective Hydrogenation of Alkenes
作者:Timothy Connolly、Zhongyu Wang、Michael A. Walker、Ivar M. McDonald、Kevin M. Peese
DOI:10.1021/ol5019739
日期:2014.9.5
chemoselective transferhydrogenation of alkenes using ruthenium metathesis catalysts is presented. Of great practicality, the transferhydrogenation reagents can be added directly to a metathesis reaction and effect hydrogenation of the product alkene in a single pot at ambient temperature without the need to seal the vessel to prevent hydrogen gas escape. The reduction is applicable to a range of alkenes and
作者:Cédric Theunissen、Melissa A. Ashley、Tomislav Rovis
DOI:10.1021/jacs.8b13663
日期:2019.5.1
development of a new system to achieve visible-light-controlled metathesis by merging olefinmetathesis and photoredox catalysis. The combination of a ruthenium metathesis catalyst bearing two N-heterocyclic carbenes with an oxidizing pyrylium photocatalyst affords excellent temporal and spatial resolution using only visible light as stimulus. Applications of this system in synthesis, as well as in polymer
A combination of a catalytic amount of a Niâphosphine complex and triethylaluminium or chlorodiethylaluminium is able to selectively cyclize a number of 1,7-heptadienes to methylidene(methyl)cyclopentanes and cyclopentenes even in cases where the dienes are prone to deallylation.
Cycloisomerization is a totally atom economic procedure which converts dienes and enynes into cyclic molecules. Modification of Grubbs’ 2nd generation catalysts by reaction with dimethylformamide provides a new species able to catalyse this transformation. Selection of suitable conditions allowed high yields and selectivity. Studies performed in order to identify the catalytic species point to a non-carbenic
Silver-Catalyzed Cascade Radical Cyclization for Stereoselective Synthesis of Exocyclic Phosphine Oxides
作者:Liuliang Mao、Yonghong Li、Shangdong Yang
DOI:10.1002/cjoc.201600707
日期:2017.3
silver‐catalyzed phosphorylation/cyclization radical cascade of 1,6‐dienes has been developed. The reaction process involves in a one‐pot operation described as an autotandem catalytic process with a cascading radical cyclization for the construction of C—P and C—C bond with high stereoselectivity. Moreover, it also affords an efficient method for the synthesis of valuable exocyclic phosphine oxides compounds