Organometallic Reactions in Aqueous Media. The Nature of the Organotin Intermediate in the Tin-Mediated Allylation of Carbonyl Compounds
摘要:
Allyl bromide and tin reacted in aqueous media to give first allyltin(II) bromide (5) and then diallyltin dibromide (4). Either organotin intermediate can react with carbonyl compounds to give the corresponding homoallylic alcohols. Competitive experiment showed that 5 was more reactive than 4.
Selective allylation of carbonyl compounds in aqueous media
作者:Cathy Einhorn、Jean-Louis Luche
DOI:10.1016/0022-328x(87)85005-2
日期:1987.3
The use of aqueous neutral media leads to excellent yields of homoallylic alcohols from reaction sof allyl halides with carbonyl compounds in the presence of tin or zinc. The stereochemicalcourse and range of application of this reaction have been investigated.
A lead-promoted allylation of carbonylcompounds with allyl bromide in a Pb/Bu4NBr/Me3SiCl/DMF system has been performed in good yields with high chemoselectivities: RCHO > R1R2CO > R1CH(OH)CO2R2>> R1CO2R2, lactone, (RCO)2O, and RCOCl.
Samarium(II) triflate was readily prepared by the reaction of samarium(III) triflate with sec-butyllithium at room temperature in THF. Its reducing ability was examined by pinacol coupling of carbonyl compounds. Sm(OTf)2 mediated Grignard-type reaction in THF-HMPA effectively; alkylation and allylation of ketones or aldehydes by simple alkyl, allyl, and benzyl halides proceeded via organosamarium intermediates
三氟甲磺酸钐 (II) 很容易通过三氟甲磺酸钐 (III) 与仲丁基锂在室温下在 THF 中反应制备。通过羰基化合物的频哪醇偶联来检测其还原能力。Sm(OTf)2在THF-HMPA中有效介导格氏型反应;通过有机钐中间体通过简单的烷基、烯丙基和苄基卤化物对酮或醛进行烷基化和烯丙基化。
Barbier allylation of aldehydes and ketones with aluminium and catalytic indium metal: an economical alternative
作者:Marcelo D. Preite、Hugo A. Jorquera-Geroldi、Andrés Pérez-Carvajal
DOI:10.3998/ark.5550190.0012.731
日期:——
An economical preparative protocol for the Barbierallylation of aldehydes and ketones in DMF, using aluminium foil in the presence of a catalytic amount of indiummetal, is reported. All yields obtained are in general similar but slightly lower than those reported for the stoichiometric indiumallylation. Aluminium alone failed to give rise to any detectable product.
Granular Indium Barbier Allylation of Carbonyl Compounds: A More Economical Protocol
作者:Marcelo Preite、Andrés Pérez-Carvajal
DOI:10.1055/s-2006-951529
日期:——
A new protocol, amenable to be used in large-scale preparations, using a cheaper form of indiummetal and mild warming is reported for the Barbierallylation of aldehydes and ketones with allyl bromide in N,N-dimethylformamide.