18273-61-5Relevant academic research and scientific papers
Controllable, Sequential, and Stereoselective C-H Allylic Alkylation of Alkenes
Qin, Ling,Sharique, Mohammed,Tambar, Uttam K.
, p. 17305 - 17313 (2019/11/03)
The direct conversion of C-H bonds into new C-C bonds represents a powerful approach to generate complex molecules from simple starting materials. However, a general and controllable method for the sequential conversion of a methyl group into a fully substituted carbon center remains a challenge. We report a new method for the selective and sequential replacement of three C-H bonds at the allylic position of propylene and other simple terminal alkenes with different carbon groups derived from Grignard reagents. A copper catalyst and electron-rich biaryl phosphine ligand facilitate the formation of allylic alkylation products in high branch selectivity. We also present conditions for the generation of enantioenriched allylic alkylation products in the presence of catalytic copper and a chiral phosphine ligand. With this approach, diverse and complex products with substituted carbon centers can be generated from simple and abundant feedstock chemicals.
A one-pot procedure for methylenating carbonyl compounds using the Nysted reagent and titanocene dichloride
Haahr, Adam,Rankovic, Zoran,Hartley, Richard C.
scheme or table, p. 3020 - 3022 (2011/06/23)
The combination of the Nysted reagent and titanocene dichloride methylenates aldehydes and ketones to give alkenes, and in a microwave-assisted process, esters and lactones give enol ethers. The methylenating agent in this one-pot procedure is presumed to be titanocene methylidene, which is the same reactive intermediate as that generated from Tebbe, Petasis and Grubbs reagents, each of which have to be prepared before use.
