140462-87-9Relevant articles and documents
Selective functionalization of a variety of hydrocarbon c(sp3)-h bonds initiated by Cp?W(NO)(CH2CMe3)(η3-CH2CHCHPh)
Wakeham, Russell J.,Baillie, Rhett A.,Patrick, Brian O.,Legzdins, Peter,Rosenfeld, Devon C.
, p. 39 - 52 (2017)
Cp?W(NO)(CH2CMe3)(η3-CH2CHCHPh) (1) effects C(sp3)-H activations of methane, ethane, propane, and n-butane exclusively at their terminal carbons and forms the corresponding Cp?W(NO)(alkyl)(η3-CH2- CHCHPh) complexes. It also activates (n-Bu)2O, 1-chloropropane, and Me4Si in a similar manner. Exposure of the Cp?W(NO)(alkyl)(η3-CH2CHCHPh) complexes to carbon monoxide results in initial 1,1-CO insertion into the newly formed tungsten-alkyl bonds and formation of the corresponding η1-acyl complexes, some of which can be isolated. Additional functionalization of the C-H activation products occurs upon exposure to CO under more forcing conditions. Such treatment produces η2-bound unsaturated-ketone complexes resulting from CO insertion into the W-alkyl σ bonds followed by cross-coupling of the η1-acyl and the η3-allyl ligands and coordination of CO at the resulting vacant coordination site at tungsten. The unsaturated ketones can be released from the metal's coordination spheres either by photolysis of the complexes in MeCN or by further exposure of them to CO. All new compounds have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of six of them have been established by single-crystal X-ray crystallographic analyses.
Regioselective ring opening and isomerization reactions of 3,4-epoxyesters catalyzed by boron trifluoride
Izquierdo, Javier,Rodriguez, Santiago,Gonzalez, Florenci V.
, p. 3856 - 3859 (2011/09/19)
Efficient ring opening of 3,4-epoxyesters with alcohols to produce 4-alkoxy-3-hydroxyesters and their isomerization into 4-ketoesters using boron trifluoride as the catalyst are presented. Both transformations are simple and efficient methods for the synthesis of the above named synthetically useful compounds.
Unsymmetrical Ketone Synthesis via a Three-Component Connection Reaction of Organozincs, Allylating Agents, and Carbon Monoxide
Yasui, Kengo,Fugami, Keigo,Tanaka, Shuji,Tamaru, Yoshinao
, p. 1365 - 1380 (2007/10/02)
A wide variety of organozincs (diethylzinc, alkylzinc halides, and organozincs 2, 5, and 9a-e, functionalized with ester and nitrile groups) undergo a three-component connection reaction with carbon monoxide and allylic benzoates or phosphates 1a-h to furnish unsymmetrical ketones, e.g., 3, 6, and 10, in good yields uder 1 atm of carbon monoxide at ambient temperature by the catalysis of tetrakis(triphenylphosphine)palladium in THF/HMPA.The regio- and stereoselectivities of the present carbonylation show marked contrast to those reported for the palladium-catalyzed carbonylation of usymmetrical allylic substrates.For example, the reaction of crotyl benzoate with octylzinc iodide provides all the possible stereo- and regioisomers, i.e., cis- and trans-2-butenyl and 1-methyl-2-propenyl octyl ketones in comparable amounts.The carbonylative coupling of carvyl phosphates, trans- and cis-1h, and γ-zincio ester 5 is stereospecific and proceeds with inversion of configuration at the allylic stereocenters to furnish cis- and trans-6h, respectively, as single diastereomers.In the absence of HMPA, the reaction feature changes dramatically and lactones 12 and 13 (composed of organozincs, carbon monoxide, and allylating agents in the ratios of 1:1:2 and 2:1:1, respectively) and symmetrical keto diesters 14 (composed of 2 mol of organozincs and 1 mol of carbon monoxide) are formed in varying ratios depending on the reaction conditions.Synthetic scope of the unsymmetrical ketones and mechanistic rationale for these unique and unprecedented reaction behaviors are discussed.
