14 research outputs found
Ethyl lactate mediated thioacetalization of aldehydes at ambient temperature
<p>Dithioacetalization reactions of aldehydes with thiols/thiophenols have been successfully achieved at room temperature by employing the green, bio-based ethyl lactate as the reaction medium. By means of this sustainable approach, a class of dithioacetals has been acquired with high diversity and efficiency.</p
A Metal- and Azide-Free Multicomponent Assembly toward Regioselective Construction of 1,5-Disubstituted 1,2,3-Triazoles
The
construction of 1,5-disubstituted 1,2,3-triazoles has been effected
through the cascade dual C–N bond formation, N–N bond
formation and an acyl migration-based C–C bond formation via
the three-component reactions of enaminones, tosylhydrazine and primary
amines. This metal- and azide-free, regioselective synthetic method
proceeds in the presence of only molecular iodine
Multicomponent Synthesis of Diverse <i>o</i>‑Arylated Benzamides via <i>o</i>‑Aminophenol (OAP) Directed C(sp<sup>2</sup>)‑H Arylation
<i>o</i>-Aminophenol (OAP) has been discovered as practical
precursor of directing group (DG) in the palladium-catalyzed aromatic
C–H arylation of benzamides. This newly identified, simple,
and low cost DG has exhibited broad substrate tolerance in the rapid
synthesis of various <i>o</i>-arylated benzamides via direct
assemblies of benzoyl chlorides, aryl iodides, and different <i>o</i>-aminophenols in the form of step economical multicomponent
reaction
Domino Reactions Involving the Branched C–N and CC Cleavage of Enaminones Toward Pyridines Synthesis
The
copper-catalyzed cascade reactions of enaminones and ammonium
chloride have led to the unprecedented synthesis of 4-unsubstituted
pyridines of both symmetrical and unsymmetrical structures. Under
the aerobic copper-catalyzed conditions, the branched transformations
of enaminones with C–N and CC bond cleavage provide
the C2-C3/C5-C6 and C4 building blocks to construct the pyridine ring,
respectively. The Cî—»C cleavage that provides the C4 atom in
the pyridine product is the first example showing the reactivity of
an enaminone as the donor of one carbon synthon
Base-Promoted Synthesis of <i>N</i>‑Substituted 1,2,3-Triazoles via Enaminone–Azide Cycloaddition Involving Regitz Diazo Transfer
The domino reactions
between NH-based secondary enaminones and
tosyl azide have been developed for the synthesis of various <i>N</i>-substituted 1,2,3-triazoles by employing <i>t</i>-BuONa as the base promoter. Through a key Regitz diazo-transfer
process with tosyl azide, the reactions proceed efficiently at room
temperature with good substrate tolerance
Copper-Catalyzed, C–C Coupling-Based One-Pot Tandem Reactions for the Synthesis of Benzofurans Using <i>o</i>‑Iodophenols, Acyl Chlorides, and Phosphorus Ylides
One-pot reactions involving acyl
chlorides, phosphorus ylides,
and <i>o</i>-iodophenols with copper catalysis have been
established for the rapid synthesis of functionalized benzofurans.
With all of these easily available and stable reactants, the construction
of the target products has been accomplished via tandem transformations
involving a key C–C coupling, leading to the formation of one
CÂ(sp<sup>2</sup>)–C bond, one CÂ(sp<sup>2</sup>)–O bond,
and one Cî—»C bond
Base-Promoted Synthesis of <i>N</i>‑Substituted 1,2,3-Triazoles via Enaminone–Azide Cycloaddition Involving Regitz Diazo Transfer
The domino reactions
between NH-based secondary enaminones and
tosyl azide have been developed for the synthesis of various <i>N</i>-substituted 1,2,3-triazoles by employing <i>t</i>-BuONa as the base promoter. Through a key Regitz diazo-transfer
process with tosyl azide, the reactions proceed efficiently at room
temperature with good substrate tolerance
Domino Reactions Involving the Branched C–N and CC Cleavage of Enaminones Toward Pyridines Synthesis
The
copper-catalyzed cascade reactions of enaminones and ammonium
chloride have led to the unprecedented synthesis of 4-unsubstituted
pyridines of both symmetrical and unsymmetrical structures. Under
the aerobic copper-catalyzed conditions, the branched transformations
of enaminones with C–N and CC bond cleavage provide
the C2-C3/C5-C6 and C4 building blocks to construct the pyridine ring,
respectively. The Cî—»C cleavage that provides the C4 atom in
the pyridine product is the first example showing the reactivity of
an enaminone as the donor of one carbon synthon
Stereoselective Synthesis of Indolyl‑<i>C</i>‑glycosides Enabled by Sequential Aminopalladation and Heck Glycosylation of 2‑Alkynylanilines with Glycals
An efficient and general approach for the synthesis of
indolyl-C-glycosides via aminopalladation and subsequent
Heck-type
glycosylation of easily available 2-alkynylanilines and glycals has
been developed. This protocol features excellent stereoselectivity,
a broad substrate scope, and mild reaction conditions. In addition,
2,3-pseudoglycals also successfully participated in this cascade reaction,
affording C2/C3-branched indolyl glycosides with high regio-/stereoselectivity.
The utility of this protocol was also demonstrated by a large-scale
reaction and diversified synthetic transformations of the desired
products
Tunable Synthesis of Disulfide-Functionalized Enaminones and 1,4-Thiazines via the Reactions of Enaminones and β‑Aminoethanethiol
The reactions of
β-aminoethanethiol with <i>N</i>,<i>N</i>-dimethyl enaminones are performed to selectively
provide disulfide-functionalized enaminones and 1,4-thiazines. By
performing the reaction in water and catalyst-free conditions, the
transamination and oxidative S–S coupling between the two substrates
take place to give disulfide-functionalized enaminones. On the other
hand, by using identical starting materials, the employment of the
CuI catalyst in dimethyl sulfoxide enables the selective generation
of 1,4-thiazines via tandem transamination and CÂ(sp<sup>2</sup>)–H
bond thiolation