692730-87-3Relevant academic research and scientific papers
Manganese-promoted β-elimination reactions: Totally stereoselective synthesis of (E)-α,β-unsaturated esters
Concellón, José M.,Rodríguez-Solla, Humberto,Del Amo, Vicente
, p. 315 - 317 (2006)
Stereoselective β-elimination of 2-bromo-3-hydroxy-esters is achieved by using non-preactivated manganese and trimethylsilyl chloride, to yield (E)-α,β-unsaturated esters with total diastereoselectivity. Georg Thieme Verlag Stuttgart.
Stereoselective olefination reactions promoted by Rieke manganese
Concellon, Jose M.,Rodriguez-Solla, Humberto,Del Amo, Vicente,Diaz, Pamela
body text, p. 2634 - 2645 (2009/12/06)
A study of the advantages of using manganese, an inexpensive and nontoxic metal, to perform stereoselective β-elimination reactions and to promote sequential olefination reactions of aldehydes to obtain α,β- unsaturated esters and amides is presented. Various elimination reactions, all of them characterized by occurring with complete stereoselectivity and in high yields, were performed using active manganese (Mn*) as metalating agent. This ability of manganese has been applied to develop a novel and direct synthesis of (E)-α,β-unsaturated esters or amides and (Z)-α,β-unsaturated α-halo esters and α-choroamides through a Mn*-mediated sequential olefination protocol of aldehydes with dichloro esters or amides and trihalo esters or trichloroamides, respectively. Georg Thieme Verlag Stuttgart.
An efficient synthesis of (E)-α,β-unsaturated ketones and esters with total stereoselectivity by using chromium dichloride
Concellón, José M.,Rodríguez-Solla, Humberto,Méjica, Carmen
, p. 3292 - 3300 (2007/10/03)
(E)-α,β-Unsaturated ketones 1 or esters 2 can be obtained with complete stereoselectivity by reaction of different 2-chloro-3-hydroxy ketones 3 or esters 4 and CrCl2. A comparative study of the results of synthesis of ketones 1 with CrCl2 or samarium is performed. A mechanism to explain both β-elimination reactions has been proposed.
Synthesis of (E)-α,β-unsaturated esters with total diastereoselectivity by using chromium dichloride
Concellón, José M.,Rodríguez-Solla, Humberto,Méjica, Carmen
, p. 2977 - 2979 (2007/10/03)
Synthesis of di- and trisubstituted (E)-α,β-unsaturated esters is easily achieved by using chromium dichloride through an elimination reaction of a diastereoisomeric mixture of α-halo-β-hydroxy esters. The starting materials were easily prepared by the aldol reaction of lithium enolates of α-chloroesters with aldehydes. A mechanism to explain this elimination process is proposed.
