6 research outputs found
Useful Access to Uncommon Thiazolo[3,2‑<i>a</i>]indoles
A practical and environmentally
benign protocol for the
assembly
of poly substituted-thiazolo[3,2-a]indoles from 3-alkylated
indoline-2-thiones and 2-halo-ketones has been developed. This metal-free
approach consists in a complete chemo/regioselective formal [3 + 2]
annulation that occurs in air, at 60 °C, and in water as the
sole reaction medium. The opportunity to vary the substitution pattern
up to six different positions, odorless manipulation of sulfurylated
compounds, very easy product isolation, and mild reaction conditions
are the main synthetic features of this method. The scaled-up experiment
and the successive transformations of the products further demonstrate
the utility of this chemistry
Tandem Aza-Wittig/Carbodiimide-Mediated Annulation Applicable to 1,2-Diaza-1,3-dienes for the One-Pot Synthesis of Fully Substituted 1,2-Diaminoimidazoles
One-pot sequential aza-Michael, Staudinger, and aza-Wittig
reactions
on 1,2-diaza-1,2-dienes (DDs) can afford fully substituted 1,2-diaminoimidazoles.
A plausible mechanism for the imidazole core formation involving an
intramolecular ring closure of the carbodiimide-derived phosphazene
intermediate is given. The reported strategy has sufficient flexibility
to allow substituted 1,2-diaminoimidazoles with orthogonal nitrogen-protective
groups to be generated from a variety of heterocumulene moieties linked
to the DDs skeleton
Effect of Hydrogenated Cardanol on the Structure of Model Membranes Studied by EPR and NMR
Hydrogenated cardanol (HC) is known
to act as an antiobesity, promising
antioxidant, and eco-friendly brominating agent. In this respect,
it is important to find the way to transport and protect HC into the
body; a micellar structure works as the simplest membrane model and
may be considered a suitable biocarrier for HC. Therefore, it is useful
to analyze the impact of HC in the micellar structure and properties.
This study reports a computer aided electron paramagnetic resonance
(EPR) and <sup>1</sup>H NMR investigation of structural variations
of cetyltrimetylammonium bromide (CTAB) micelles upon insertion of
HC at different concentrations and pH variations. Surfactant spin
probes inserted in the micelles allowed us to get information on the
structure and dynamics of the micelles and the interactions between
HC and CTAB. The formation of highly packed HC-CTAB mixed micelles
were favored by the occurrence of both hydrophobic (chain–chain)
and hydrophilic (between the polar and charged lipid heads) interactions.
These interactions were enhanced by neutralization of the acidic HC
heads. Different HC localizations into the micelles and micellar structures
were identified by changing HC/CTAB relative concentrations and pH.
The increase in HC concentration generated mixed micelles characterized
by an increased surfactant packing. These results suggested a rod-like
shape of the mixed micelles. The increase in pH promoted the insertion
of deprotonated HC into less packed micelles, favored by the electrostatic
head–head interactions between CTAB and deprotonated-HC surfactants
Powerful Approach to Heterocyclic Skeletal Diversity by Sequential Three-Component Reaction of Amines, Isothiocyanates, and 1,2-Diaza-1,3-dienes
By highly efficient, one-pot, three-component reactions,
combining
one set of 1,2-diaza-1,3-dienes (DDs), primary amines, and isothiocyanates
in a different sequential order of addition, heterocyclic skeletal
diversity can be achieved. The key feature discriminating the different
heterocyclic core formation is the availability of the <i>N</i> or <i>S</i> heteronucleophile to give the first Michael
addition step affording regioselective substituted 2-thiohydantoins
or 2-iminothiazolidinones. The hydrazone or enehydrazino side chain
at the 5-position of both heterocycles represents a valuable functionality
to reach novel 5-hydroxyethylidene derivatives difficult to obtain
by other methods
Effect of Hydrogenated Cardanol on the Structure of Model Membranes Studied by EPR and NMR
Hydrogenated cardanol (HC) is known
to act as an antiobesity, promising
antioxidant, and eco-friendly brominating agent. In this respect,
it is important to find the way to transport and protect HC into the
body; a micellar structure works as the simplest membrane model and
may be considered a suitable biocarrier for HC. Therefore, it is useful
to analyze the impact of HC in the micellar structure and properties.
This study reports a computer aided electron paramagnetic resonance
(EPR) and <sup>1</sup>H NMR investigation of structural variations
of cetyltrimetylammonium bromide (CTAB) micelles upon insertion of
HC at different concentrations and pH variations. Surfactant spin
probes inserted in the micelles allowed us to get information on the
structure and dynamics of the micelles and the interactions between
HC and CTAB. The formation of highly packed HC-CTAB mixed micelles
were favored by the occurrence of both hydrophobic (chain–chain)
and hydrophilic (between the polar and charged lipid heads) interactions.
These interactions were enhanced by neutralization of the acidic HC
heads. Different HC localizations into the micelles and micellar structures
were identified by changing HC/CTAB relative concentrations and pH.
The increase in HC concentration generated mixed micelles characterized
by an increased surfactant packing. These results suggested a rod-like
shape of the mixed micelles. The increase in pH promoted the insertion
of deprotonated HC into less packed micelles, favored by the electrostatic
head–head interactions between CTAB and deprotonated-HC surfactants
Divergent Approach to Thiazolylidene Derivatives: A Perspective on the Synthesis of a Heterocyclic Skeleton from β‑Amidothioamides Reactivity
Herein we report a domino protocol
able to reach regioselectively
thiazolylidene systems by combining the reactive peculiarities of
both β-amidothioamides (ATAs) and 1,2-diaza-1,3-dienes (DDs).
Depending on the reaction conditions and/or the nature of the residue
at C4 of the heterodiene system, ATAs can act as hetero-mononucleophiles
or hetero-dinucleophiles in the diversified thiazolylidene ring assembly