122617-93-0Relevant articles and documents
Catalytic asymmetric synthesis of cyclic α-allylated α-fluoroketones
Burger,Barron,Tunge
, p. 2824 - 2826 (2006)
This manuscript details the development of an asymmetric, palladium-catalyzed, decarboxylative coupling of fluoroenolates with allyl electrophiles. Georg Thieme Verlag Stuttgart.
Enantioselective decarboxylative alkylation reactions: Catalyst development, substrate scope, and mechanistic studies
Behenna, Douglas C.,Mohr, Justin T.,Sherden, Nathaniel H.,Marinescu, Smaranda C.,Harned, Andrew M.,Tani, Kousuke,Seto, Masaki,Ma, Sandy,Novak, Zoltan,Krout, Michael R.,McFadden, Ryan M.,Roizen, Jennifer L.,Enquist Jr., John A.,White, David E.,Levine, Samantha R.,Petrova, Krastina V.,Iwashita, Akihiko,Virgil, Scott C.,Stoltz, Brian M.
supporting information; experimental part, p. 14199 - 14223 (2012/02/01)
α-Quaternary ketones are accessed through novel enantioselective alkylations of allyl and propargyl electrophiles by unstabilized prochiral enolate nucleophiles in the presence of palladium complexes with various phosphinooxazoline (PHOX) ligands. Excellent yields and high enantiomeric excesses are obtained from three classes of enolate precursor: enol carbonates, enol silanes, and racemic β-ketoesters. Each of these substrate classes functions with nearly identical efficiency in terms of yield and enantioselectivity. Catalyst discovery and development, the optimization of reaction conditions, the exploration of reaction scope, and applications in target-directed synthesis are reported. Experimental observations suggest that these alkylation reactions occur through an unusual inner-sphere mechanism involving binding of the prochiral enolate nucleophile directly to the palladium center. Sly as a PHOX: The development of an enantioselective decarboxylative palladium-catalyzed allylic alkylation reaction, utilizing phosphinooxazoline ligands, is described. The catalyst is applied to a range of allyl enol carbonate, silyl enol ether, and allyl β-ketoester substrates to provide alkylated ketone products in excellent yield and good ee (see scheme). The utility of these products is demonstrated by their use in several asymmetric syntheses. Mechanistic studies are reported suggesting an unusual inner-sphere mechanism. Copyright
Deracemization of quaternary stereocenters by Pd-catalyzed enantioconvergent decarboxylative allylation of racemic β-ketoesters
Mohr, Justin T.,Behenna, Douglas C.,Harned, Andrew M.,Stoltz, Brian M.
, p. 6924 - 6927 (2007/10/03)
(Chemical Equation Presented) Stereochemical alchemy! Racemic allyl β-ketoesters allow the regiocontrolled formation of enolates, where the same catalyst is intimately involved in both the stereoablative (C-C bond-breaking) and stereoselective (C-C bond-f
Synthesis of α-Fluoroketones Based on Palladiom-Catalyzed Decarboxylation Reactions of Allyl β-Keto Carboxylates
Shimizu, Isao,Ishii, Hirotoshi
, p. 487 - 496 (2007/10/02)
Fluorination of allyl β-keto carboxylates using N-fluoro-2,4,6-pyridinium triflate gave allyl α-fluoro-β-keto carboxylates.Reaction of allyl α-fluoro-β-keto carboxylates with formic acid in the presence of palladium-phosphine catalyst gave α-fluoro ketone
