Three-Step Metal-Promoted
Allene-Based Preparation
of Bis(heterocyclic) Cyclophanes from Carbonyl Compounds
Benito Alcaide
Pedro Almendros
M. Teresa Quirós
Carlos Lázaro
M. Rosario Torres
10.1021/jo500993x.s001
https://acs.figshare.com/articles/journal_contribution/Three_Step_Metal_Promoted_Allene_Based_Preparation_of_Bis_heterocyclic_Cyclophanes_from_Carbonyl_Compounds/2277520
A straightforward
metal-mediated method for the synthesis of bis(dihydrofuryl)
cyclophane scaffolds from carbonyl compounds has been developed. The
combination of the dihydrofuran moiety with different heterocycles
such as β-lactams and sugars allows high levels of skeletal
diversity. The process comprises indium-promoted one-pot carbonyl
bis(allenylation) and gold- or palladium-catalyzed double cyclization
in the resulting bis(allenols), followed by selective ruthenium-catalyzed
macrocyclization. In some cases, the method has been successfully
applied to the synthesis of the challenging <i>Z</i>-isomers.
The <i>E</i>- versus <i>Z</i>-stereochemistry
of the metathesis-formed double bonds could not be assigned taking
into consideration the usual coupling constants criteria, but a diagnostic
based on the chemical shifts of the two olefinic protons located at
the macrocyclic double bond was established.
2014-07-03 00:00:00
constants criteria
carbonyl compounds
bond
method
olefinic protons
bi
dihydrofuran moiety
chemical shifts
Carbonyl CompoundsA
synthesis