Multi-Metal-Catalyzed Oxidative Radical Alkynylation with Terminal Alkynes: A New Strategy for C(sp3)-C(sp) Bond Formation
A new way for C(sp3)-C(sp) cross-coupling with terminal alkynes has been developed by using a multi-metal-catalyzed reaction strategy. Alkyl radicals generated from different approaches are able to couple with terminal alkynes by judicious selection of the catalyst combination. This reaction protocol offers an efficient alternative approach for the synthesis of substituted alkynes from terminal alkynes besides traditional Sonogashira coupling. Mechanistic studies have also been carried out to clarify the role of each metal catalyst in the radical alkynylation processes. The reactions were found to go through radical reaction pathways. Synergistic cooperation of the metal catalysts is the key for controlling the reaction selectivity of alkyl radicals toward C(sp3)-C(sp) bond formation.
Liquid-Liquid Extraction Protocol for the Removal of Aldehydes and Highly Reactive Ketones from Mixtures
The reaction of the bisulfite ion with aldehydes to form charged bisulfite adducts is a well-established method for the purification of aldehydes. This reaction has been modified to create a convenient liquid-liquid extraction method for the removal of aldehydes from mixtures. The use of a water-miscible solvent allows the reaction to occur during a simple 30 s shaking protocol by increasing the contact between the bisulfite ion and the aldehyde. The introduction of an immiscible solvent allows for the extraction of the uncharged organic components away from the bisulfite adduct. The developed protocol is applicable to a wide range of aldehydes, including sterically hindered neopentyl aldehydes. Sterically unhindered cyclic and linear ketones, as well as highly electrophilic ketones, are also removed using this protocol. The mild conditions tolerate a wide range of functional groups, allowing for excellent aldehyde contaminant removal rates with high levels of recovery of the desired component.
Boucher, Maria M.,Furigay, Maxwell H.,Quach, Phong K.,Brindle, Cheyenne S.
p. 1394 - 1403
(2017/09/23)
Preparation of iniidazolin-2-iminato molybdenum and tungsten benzylidyne complexes: A new pathway to highly active alkyne metathesis catalysts
The reaction of [PhC=MBr3(dme)] (dme = 1,2-dimethoxyethane) with the hexafluoro-fert-butoxides LiJ. or KX [X = OC(CF3)2Me] afforded the benzylidyne complexes [PhC=MX3(dme)] (2a: M = W, 2b: M = Mo), which further
Haberlag, Birte,Wu, Xian,Brandhorst, Kai,Grunenberg, Joerg,Daniliuc, Constantin G.,Jones, Peter G.,Tamm, Matthias
supporting information; experimental part
p. 8868 - 8877
(2010/09/08)
Synthesis of substituted α-methylene-γ-butyrolactones from chloroformates via palladium catalysed cyclisation-anion capture
Cyclisation of chloroformates onto proximate alkyne functionality in the presence of a Pd(0) catalyst followed by anion capture affords α-methylene-γ-butyrolactone derivatives in moderate to good yields.
Grigg,Savic
p. 2381 - 2382
(2007/10/03)
More Articles about upstream products of 132699-38-8