183253-89-6Relevant academic research and scientific papers
Asymmetric formal trans -dihydroxylation and trans -aminohydroxylation of α,β-unsaturated aldehydes via an organocatalytic reaction cascade
Albrecht, Lukasz,Jiang, Hao,Dickmeiss, Gustav,Gschwend, Bjoern,Hansen, Signe Grann,Jorgensen, Karl Anker
supporting information; experimental part, p. 9188 - 9196 (2010/08/21)
This study demonstrates the first formal asymmetric trans-dihydroxylation and trans-aminohydroxylation of α,β-unsaturated aldehydes in an organocatalytic multibond forming one-pot reaction cascade. This efficient process converts α,β-unsaturated aldehydes into optically active trans-2,3-dihydroxyaldehydes and trans-3-amino-2-hydroxyaldehydes with the aldehyde moiety protected as an acetal. The elaborated one-pot protocol proceeds via the formation of 2,3-epoxy and 2,3-aziridine aldehyde intermediates, which subsequently participate in a novel NaOMe-initiated rearrangement reaction leading to the formation of acetal protected trans-2,3-dihydroxyaldehydes and trans-3-amino-2-hydroxyaldehydes in a highly stereoselective manner. Advantageously, this multibond forming reaction cascade can be performed one-pot, thereby minimizing the number of manual operations and purification procedures required to obtain the products. Additionally, for the purpose of trans-aminohydroxylation of the α,β-unsaturated aldehydes, a new enantioselective aziridination protocol using 4-methyl-N-(tosyloxy) benzenesulfonamide as the nitrogen source has been developed. The mechanism of the formal trans-dihydroxylation and trans-aminohydroxylation of α,β-unsaturated aldehydes is elucidated by various investigations including isotopic labeling studies. Finally, the products obtained were applied in the synthesis of numerous important molecules.
A Thermodynamic Preference of Chiral N-Methanesulfonyl and N-Arenesulfonyl 2,3-cis-3-Alkyl-2-Vinylaziridines over Their 2,3-Trans-Isomers: Useful Palladium(0)-Catalyzed Equilibration Reactions for the Synthesis of (E)-Alkene Dipeptide Isosteres
Ibuka, Toshiro,Mimura, Norio,Aoyama, Hiroshi,Akaji, Masako,Ohno, Hiroaki,Miwa, Yoshihisa,Taga, Tooru,Nakai, Kazuo,Tamamura, Hirokazu,Fujii, Nobutaka,Yamamoto, Yoshinori
, p. 999 - 1015 (2007/10/03)
Palladium(0)-catalyzed reactions of N-methanesulfonyl- or N-(arenesulfonyl)-3-alkyl-2-vinylaziridines reveal that 2,3-cis-isomers are more stable than the corresponding 2,3-trans-isomers in accord with ab initio calculations. A highly stereoselective synthetic route to (E)-alkene dipeptide isosteres having desired stereochemistries from 2,3-cis-3-isobutyl-2-vinylaziridine by the use of organocopper chemistry is also presented.
Synthesis of functionalized cyclopropanes by MIRC reactions of aziridinyl-methylenemalonates
Funaki, Ikuo,Bell, Roel P.L.,Thijs, Lambertus,Zwanenburg, Binne
, p. 12253 - 12274 (2007/10/03)
The synthesis of cyclopropane derivatives via a MIRC reaction of aziridinyl-methylene-malonates is described. In this way it is possible to introduce a hydrogen, a phenylthio, a tributylstannyl and an olefinic function at the cyclopropane ring, that further contains an alkylamino substituent. Addition of CuCN catalyzed Grignard reagents gave the most promising results. The diastereoselectivity was dependent on the aziridine nitrogen substituent and the bulkiness of the reagent.
SN2'-Reactions of Peptide Aziridines. A Cuprate-Based Approach to (E)-Alkene Isosteres
Wipf, Peter,Fritch, Paul C.
, p. 4875 - 4886 (2007/10/02)
Alkenylaziridines were prepared from allylic alcohols via Sharpless epoxidation, oxirane to aziridine conversion under modified Staudinger conditions, and Wittig chain extension.Alternatively, β-hydroxy α-amino acids such as threonine can serve as readily
