68854-59-1Relevant articles and documents
Electrophilic Iron Catalyst Paired with a Lithium Cation Enables Selective Functionalization of Non-Activated Aliphatic C?H Bonds via Metallocarbene Intermediates
Hernán-Gómez, Alberto,Rodríguez, Mònica,Parella, Teodor,Costas, Miquel
, p. 13904 - 13911 (2019/08/30)
Combining an electrophilic iron complex [Fe(Fpda)(THF)]2 (3) [Fpda=N,N′-bis(pentafluorophenyl)-o-phenylenediamide] with the pre-activation of α-alkyl-substituted α-diazoesters reagents by LiAl(ORF)4 [ORF=(OC(CF3)3] provides unprecedented access to selective iron-catalyzed intramolecular functionalization of strong alkyl C(sp3)?H bonds. Reactions occur at 25 °C via α-alkyl-metallocarbene intermediates, and with activity/selectivity levels similar to those of rhodium carboxylate catalysts. Mechanistic investigations reveal a crucial role of the lithium cation in the rate-determining formation of the electrophilic iron-carbene intermediate, which then proceeds by concerted insertion into the C?H bond.
Regio- and Stereocontrol in the Reactions of α-Halo-β,γ-enoates and α- O -Phosphono-β,γ-enenitriles with Organocuprates
Dieter, R. Karl,Picado, Alfredo
, p. 11125 - 11138 (2015/02/19)
The reactions of (Z)- and (E)-ethyl 2-chloro-3-octenoate (4a and 17) and (E)- and (Z)-diethyl (1-cyano-2-heptenyl)phosphate (21a and 21b) with organocuprates were investigated as potential substrates for preparing γ-substituted α,β-enoates and enenitriles. In these copper-mediated allylic substitution reactions, the Z-isomer 4a displayed complete regio- and stereoselectivity (i.e., E:Z), while the regio- and stereoselectivity for E-isomer 17 varied as a function of solvent, cuprate reagent, transferable ligand, and cuprate counterion (e.g., Li+ vs MgX+). Excellent selectivities could be achieved with 17 and nBuCuCNLi in Et2O. Conditions for improved selectivities in the reactions of allylic cyanophosphates over those previously reported were found. A series of relative rate and competition experiments was performed, and the degree of regio- and stereoselectivity for each system was rationalized in the light of the current mechanistic understanding of cuprate-mediated allylic substitution reactions.
A convenient one-pot PCC oxidation-Wittig reaction of alcohols
Bressette, Andrew R.,Glover IV, Louis C.
, p. 738 - 740 (2007/10/03)
A simple one-pot process for the PCC oxidation of alcohols followed by in situ trapping of the aldehyde with a Wittig reagent is described.
