A two-step reaction sequence starting with the indium-mediatedallenylation of aldehydes with 4-bromo-2-butyn-1-ols and subsequent ozonolysis of the resulting allenylic product was developed to generate a variety of dihydroxyacetone derivatives. The regioselectivity of the indium-promoted C–C bond-forming reaction can be manipulated through hydroxy protecting groups on 4-bromo-2-butyn-1-ol, yielding
Metal-Catalyzed Cycloetherification Reactions of β,γ- and γ,δ-Allendiols: Chemo-, Regio-, and Stereocontrol in the Synthesis of Oxacycles
作者:Benito Alcaide、Pedro Almendros、Rocío Carrascosa、Teresa Martínez del Campo
DOI:10.1002/chem.201001520
日期:2010.11.22
and stereocontrolled metal‐catalyzed oxycyclization reactions of β,γ‐ and γ,δ‐allendiols, which were readily prepared from (R)‐2,3‐O‐isopropylideneglyceraldehyde. The application of PdII, PtII, AuIII, or LaIII salts as the catalysts gives controlled access to differently sized oxacycles in enantiopure form. Usually, chemoselective cyclization reactions occurred exclusively by attack of the secondary hydroxy
Organoseleno-Catalyzed Synthesis of α,β-Unsaturated α′-Alkoxy Ketones from Allenes Enabled by Se···O Interactions
作者:Mireia Toledano-Pinedo、Teresa Martínez del Campo、Marta Tiemblo、Israel Fernández、Pedro Almendros
DOI:10.1021/acs.orglett.0c01288
日期:2020.5.15
α,β-Unsaturated α'-alkoxy ketones have been prepared under mild conditions from allenes using water as the oxygen source and without the necessity of metals. The organocatalytic oxygenation-rearrangement sequence displays an exquisite chemo-, stereo-, and site-selectivity as well as good functional group compatibility. DFT calculations suggest that stabilizing noncovalent Se···O interactions may be