86487-17-4Relevant articles and documents
Stannylation of Aryl Halides, Stille Cross-Coupling, and One-Pot, Two-Step Stannylation/Stille Cross-Coupling Reactions under Solvent-Free Conditions
Gribanov, Pavel S.,Golenko, Yulia D.,Topchiy, Maxim A.,Minaeva, Lidiya I.,Asachenko, Andrey F.,Nechaev, Mikhail S.
supporting information, p. 120 - 125 (2018/01/17)
Solvent-free protocols for palladium-catalyzed stannylation of aryl halides, Stille cross-coupling, and one-pot, two-step stannylation/Stille cross-coupling (SSC) are reported for the first time. (Het)aryl halides bearing acceptor, donor, as well as sterically demanding substituents are stannylated and/or coupled in high yields. The reactions are catalyzed by conventional palladium(II) acetate/PCy3 [Pd(OAc)2/PCy3] under air, using available base CsF, and without the use of high purity reagents. The developed synthetic procedures are versatile, robust, and easily scalable. The absence of solvent, and the elimination of isolation procedures of aryl stannanes makes the SSC protocol simple, step economical, and highly efficient for the synthesis of biaryls in a one-pot two-step procedure.
Radical Cyclisation of α-Halo Aluminium Acetals: A Mechanistic Study
Bénéteau, Romain,Boussonnière, Anne,Rouaud, Jean-Christophe,Lebreton, Jacques,Graton, Jéro?me,Jacquemin, Denis,Sebban, Muriel,Oulyadi, Hassan,Hamdoun, Ghanem,Hancock, Amber N.,Schiesser, Carl H.,Dénès, Fabrice
, p. 4809 - 4824 (2016/04/05)
α-Bromo aluminium acetals are suitable substrates for Ueno-Stork-like radical cyclisations affording γ-lactols and acid-sensitive methylene-γ-lactols in high yields. The mechanistic study herein sets the scope and limitation of this reaction. The influence of the halide (or chalcogenide) atom X (X=Cl, Br, I, SPh, SePh) in the precursors α-haloesters, as well as influence of the solvent and temperature was studied. The structure of the aluminium acetal intermediates resulting from the reduction of the corresponding α-haloesters has been investigated by low-temperature 13C-INEPT diffusion-ordered NMR spectroscopy (DOSY) experiments and quantum calculations, providing new insights into the structures of these thermally labile intermediates. Oxygen-bridged dimeric structures with a planar Al2O2 ring are proposed for the least hindered aluminium acetals, while monomeric structures seem to prevail for the most hindered species. A comparison against the radical cyclisation of aluminium acetals derived from allyl and propargyl alcohols with the parent Ueno-Stork has been made at the BHandHLYP/6-311++G(d,p) level of theory, highlighting mechanistic similarities and differences.
Sonochemical synthesis of bis(tri-n-butylstannyl) aromatic compounds via Barbier-like reactions
Gerbino, Darío C.,Fidelibus, Pablo M.,Mandolesi, Sandra D.,Ocampo, Romina A.,Scoccia, Jimena,Podestá, Julio C.
, p. 24 - 32 (2013/10/01)
This paper reports a study of the synthesis of aryltri-n-butylstannanes via a sonochemical Barbier reaction of aryl- and heteroaryl bromides with bis(tri-n-butyltin) oxide (2) in THF. Our results demonstrate that, despite previous reports on contrary, the aryltributylstannanes can also be obtained under the same reaction conditions via sonicated reactions between aryl monobromides and tri-nbutyltin chloride (2). A comparative study of the reactions of electrophiles 2 and 3 with bromobenzene, 2-bromopyridin, o- and m-bromoanisole, m-bromotoluene, 9-bromophenthrene, and 9-bromoanthracene, indicates that the corresponding aryl- and heteroaryl-tri-n-butylstannyl derivatives are obtained in about the sameyields. Best reaction conditions and the results obtained in the investigation of the sonicated reactions between several aromatic and heteroaromatic dibromides are also reported. It was found that the reactions using 1,2-, 1,3-, and 1,4-dibromobenzenes, 4,40-dibromobiphenyl, 1,4-dibromonaphthalene, 2,5-and 3,5-dibromopyridines, and 2,5-dibromothiophene lead to the corresponding bis(tri-n-butylstannylated) derivatives in many cases in very high yields. Also the excellent results obtained in the sonicated reactions of 1,3,5-tribromobenzene with 2 and 3 are reported.
