95124-06-4Relevant articles and documents
Regioselective Asymmetric Allylic Alkylation Reaction of α -Cyanoacetates Catalyzed by a Heterobimetallic Platina-/Palladacycle
Weiss, Marcel,Holz, Julia,Peters, Ren
, p. 210 - 227 (2016/01/20)
Allylic substitution reactions provide a valuable tool for the functionalization of CH acidic pronucleophiles. Often, control over the stereocenter generated at the nucleophilic reactant is still a challenge. The majority of studies that address this issue employ metal complexes with a low metal oxidation state (e.g. Pd0) to form allyl complexes through oxidative addition. In this article we describe the use of heterobimetallic PtII/PdII complexes, which probably activate the olefinic substrates through an SN2′ pathway. The reaction of α-cyanoacetates delivers linear allylation products with exclusive regioselectivity and high E/Z-selectivity for the new C=C double bond. Although the enantioselectivities attained are moderate, they are significantly higher than with related mono-PdII or -PtII catalysts or the corresponding bis-PdII complex, which indicates cooperation of the different metals. Control experiments suggest simultaneous activation of both reaction partners.
A versatile preparation of alpha,beta-unsaturated lactones from homoallylic alcohols.
Keck,Li,Knutson
, p. 411 - 413 (2008/02/12)
[formula: see text] A new method for the synthesis of alpha,beta-unsaturated lactones from beta-acetoxy aldehydes by reaction with the lithium enolate of methyl acetate was developed. The reaction is relatively insensitive to structural changes in the ald