75316-62-0Relevant academic research and scientific papers
P-Chiral Monophosphorus Ligands for Asymmetric Copper-Catalyzed Allylic Alkylation
Xiong, Wenrui,Xu, Guangqing,Yu, Xinhong,Tang, Wenjun
, p. 4003 - 4013 (2019/06/24)
Asymmetric copper-catalyzed allylic alkylation between allyl bromides and alkyl Grignard reagents using a P-chiral monophosphorus ligand is described. A range of terminal olefins bearing tertiary or quaternary carbon centers were formed in good branched/linear selectivities and excellent enantioselectivities at copper loadings as low as 0.5 mol %.
Improvements and Applications of the Transition Metal-Free Asymmetric Allylic Alkylation using Grignard Reagents and Magnesium Alanates
Grassi, David,Alexakis, Alexandre
supporting information, p. 3171 - 3186 (2015/11/03)
Two new N-heterocyclic carbene (NHC) ligands have been synthesized and employed in the transition metal-free asymmetric allylic alkylation (AAA) mediated by Grignard reagents and magnesium alanates. The employment of these ligands showed high yields and improved regio- and enantioselectivity in the formation of tertiary and quaternary stereocenters. Moreover, the low catalyst loading (up to 0.3 mol%) and high scalability (up to 10 mmol) of this improved methodology provide a convenient access to biologically active compounds and synthetically valuable intermediates.
Copper-free asymmetric allylic alkylation with a grignard reagent: Design of the ligand and mechanistic studies
Grassi, David,Dolka, Chrysanthi,Jackowski, Olivier,Alexakis, Alexandre
supporting information, p. 1466 - 1475 (2013/02/25)
The Cu-free asymmetric allylic alkylation, catalysed by NHC, with Grignard reagents is reported on allyl bromide derivatives with good results. The enantioselectivity was quite homogeneous (around 85 % ee) on large and various substrates, regardless of the nature of the Grignard reagent. The formation of stereogenic quaternary centres was highly regioselective for both aliphatic and aromatic derivatives with good enantiomeric excess (up to 92 % ee). The methodology developed was found to be complementary with the Cu-catalysed version. Several new NHCs were tested with improved efficiency. In addition, mechanistic studies, using NMR spectroscopy, led to the discovery of the catalytically active species. Copyright
TERPENE UND TERPENDERIVATE-IX α-CURCUMEN, β-CURCUMEN UND ar-TURMERON DURCH ALKYLIERUNG VON C5- UND C10-DITHIANEN
Bokel, H. H.,Hoppmann, A.,Weyerstahl, P.
, p. 651 - 654 (2007/10/02)
The dithiane 11 is alkylated with prenyl bromide to give 12.Hydrogenolysis of 12 with Raney-Nickel yields α-curcumene (6), hydrolysis of 12 gives the ketone 13.Prenal dithiane (14) is alkylated with 8 to give 15. ar-Turmerone (16) is formed by hydrolysis of 15.Reaction of 15 with sodium in liquid ammonia leads to a mixture of α-curcumene (6) and β-curcumene (10).
