8 research outputs found
Synthesis of Tetraarylmethanes by the Triflic Acid-Promoted Formal Cross-Dehydrogenative Coupling of Triarylmethanes with Arenes
Tantalum Catalyzed Hydroaminoalkylation for the Synthesis of α- and β‑Substituted <i>N</i>‑Heterocycles
Unprotected secondary amines are directly alkylated by C–H functionalization adjacent to nitrogen, thereby opening new routes toward the synthesis of α- and β-alkylated <i>N</i>-heterocycles. α-Alkylated piperidine, piperazine, and azepane products are prepared from heterocycles and alkenes in an atom-economic reaction with excellent regio- and diastereoselectivity. β-Alkylated <i>N</i>-heterocycles are synthesized via a scalable one-pot alkylation/cyclization procedure generating 3-methylated azetidines, pyrrolidines, and piperidines
Development of Versatile Sulfone Electrophiles for Suzuki–Miyaura Cross-Coupling Reactions
The
development of fluorinated sulfone derivatives as versatile
electrophiles for Suzuki–Miyaura cross-coupling reactions is
described. Introducing electron-withdrawing groups on the aryl ring
of the sulfone facilitates the Pd-catalyzed activation of C–SO<sub>2</sub> bonds. Cross-coupling reactions with fluorinated sulfone
electrophiles are reported, leading to a variety of multiply arylated
products in good yields. The reactivity of this unusual electrophile
is benchmarked versus common electrophiles and its use in iterative
cross-couplings for concise synthesis of biologically active molecules
is described
Tantalum Catalyzed Hydroaminoalkylation for the Synthesis of α- and β‑Substituted <i>N</i>‑Heterocycles
Unprotected secondary amines are directly alkylated by C–H functionalization adjacent to nitrogen, thereby opening new routes toward the synthesis of α- and β-alkylated <i>N</i>-heterocycles. α-Alkylated piperidine, piperazine, and azepane products are prepared from heterocycles and alkenes in an atom-economic reaction with excellent regio- and diastereoselectivity. β-Alkylated <i>N</i>-heterocycles are synthesized via a scalable one-pot alkylation/cyclization procedure generating 3-methylated azetidines, pyrrolidines, and piperidines
Tantalum Catalyzed Hydroaminoalkylation for the Synthesis of α- and β‑Substituted <i>N</i>‑Heterocycles
Unprotected secondary amines are directly alkylated by C–H functionalization adjacent to nitrogen, thereby opening new routes toward the synthesis of α- and β-alkylated <i>N</i>-heterocycles. α-Alkylated piperidine, piperazine, and azepane products are prepared from heterocycles and alkenes in an atom-economic reaction with excellent regio- and diastereoselectivity. β-Alkylated <i>N</i>-heterocycles are synthesized via a scalable one-pot alkylation/cyclization procedure generating 3-methylated azetidines, pyrrolidines, and piperidines
Bis(amidate)bis(amido) Titanium Complex: A Regioselective Intermolecular Alkyne Hydroamination Catalyst
An
efficient and selective bisÂ(amidate)ÂbisÂ(amido) titanium precatalyst
for the anti-Markovnikov hydroamination of alkynes is reported. Hydroamination
of terminal and internal alkynes with primary alkylamines, arylamines,
and hydrazines is promoted by 5–10 mol % of Ti catalyst. Various
functional groups are tolerated including esters, protected alcohols,
and imines. The in situ generated complex shows comparable catalytic
activity, demonstrating its synthetic versatility for benchtop application.
Applications of this catalyst for the synthesis of amino alcohols
and a one-pot procedure for indole synthesis are described. A mechanistic
proposal that invokes turnover-limiting protonolysis is presented
to rationalize the observed regioselectivities