Efficient Carbazole Synthesis via Pd/Cu-Cocatalyzed Cross-Coupling/Isomerization of 2‑Allyl-3-iodoindoles and Terminal Alkynes

The Pd/Cu-cocatalyzed one-pot reaction of 2-allyl-3-iodo-1-tosyl-1<i>H</i>-indoles and terminal alkynes afforded carbazoles highly efficiently via sequential carbon–carbon coupling, isomerization, cyclization, and aromatization forming a benzene ring. Both Pd and Cu are responsible for the coupling step, while K₂CO₃ was observed to be critical for the subsequent cyclization

Coupling and Cyclization of <i>o</i>‑Iodoanilines and Propargylic Bromides via Allenes: An Efficient Entry to Indomethacin

A sequential allene synthesis and cyclization has been realized in a one-pot manner. A Pd(0)-catalyzed one-pot reaction of <i>N</i>-Ts or -Ms 2-iodoanilines and propargylic bromides afforded indoles with pharmaceutical importance highly efficiently with diversity via sequential carbon–carbon bond coupling forming allenes and azapalladation. With this newly established methodology, an efficient approach to indomethacin, an anti-inflammatory drug (NSAID), has been accomplished

Coupling and Cyclization of <i>o</i>‑Iodoanilines and Propargylic Bromides via Allenes: An Efficient Entry to Indomethacin

A sequential allene synthesis and cyclization has been realized in a one-pot manner. A Pd(0)-catalyzed one-pot reaction of <i>N</i>-Ts or -Ms 2-iodoanilines and propargylic bromides afforded indoles with pharmaceutical importance highly efficiently with diversity via sequential carbon–carbon bond coupling forming allenes and azapalladation. With this newly established methodology, an efficient approach to indomethacin, an anti-inflammatory drug (NSAID), has been accomplished

Efficient Carbazole Synthesis via Pd/Cu-Cocatalyzed Cross-Coupling/Isomerization of 2‑Allyl-3-iodoindoles and Terminal Alkynes

The Pd/Cu-cocatalyzed one-pot reaction of 2-allyl-3-iodo-1-tosyl-1<i>H</i>-indoles and terminal alkynes afforded carbazoles highly efficiently via sequential carbon–carbon coupling, isomerization, cyclization, and aromatization forming a benzene ring. Both Pd and Cu are responsible for the coupling step, while K₂CO₃ was observed to be critical for the subsequent cyclization

Highly Selective Cascade C–C Bond Formation via Palladium- Catalyzed Oxidative Carbonylation–Carbocyclization–Carbonylation–Alkynylation of Enallenes

A highly efficient palladium-catalyzed oxidative cascade reaction of enallenes undergoing overall four C–C bond formations has been developed. The insertion cascade proceeds via carbonylation–carbocyclization–carbonylation–alkynylation involving sequential insertion of carbon monoxide, olefin, and carbon monoxide. Furthermore, different types of terminal alkynes and functionalized enallenes have been investigated and found to undergo the cascade reaction under mild reaction conditions

Highly Efficient Cascade Reaction for Selective Formation of Spirocyclobutenes from Dienallenes via Palladium-Catalyzed Oxidative Double Carbocyclization–Carbonylation–Alkynylation

A highly selective cascade reaction that allows the direct transformation of dienallenes to spirocyclobutenes (spiro[3.4]­octenes) as single diastereoisomers has been developed. The reaction involves formation of overall four C–C bonds and proceeds via a palladium-catalyzed oxidative transformation with insertion of olefin, olefin, and carbon monoxide. Under slightly different reaction conditions, an additional CO insertion takes place to give spiro[4.4]­nonenes with formation of overall five C–C bonds

Study on the Thermoelectric Properties of n‑Type Polycrystalline SnSe by CeCl₃ Doping

SnSe is a promising medium-temperature thermoelectric material due to its extremely low thermal conductivity and tunable electronic transport properties. In this work, n-type SnSe0.95 polycrystals doped with CeCl3 are synthesized by a melting method combined with a spark plasma sintering (SPS) process. The samples have highly textured structures and anisotropic thermoelectric properties. CeCl3 doping has a favorable effect on the electronic transport above 473 K, which may benefit from the excitation of the introduced impurity energy level. Moreover, the thermal conductivity is significantly reduced due to the phonon scattering by point defects. Finally, a peak ZT value of 1.17 is obtained at 773 K in SnSe0.95–0.5 mol % CeCl3, which paves the way for improving the thermoelectric performance of n-type SnSe via rare-earth halide doping

Conformational Effect of Polymorphic Terfluorene on Photophysics, Crystal Morphologies, and Lasing Behaviors

Molecular conformation is an important factor in flexible organic molecules and deeply influences their physical and chemical properties. Here, a model fluorene trimer, 2,2′:7′,2″-ter­(9,9-di­methyl­fluorene) (TDMeF), was designed and synthesized to investigate the effect of conformational diversity of oligofluorene on the morphologies of microcrystals and photophysical properties. Single crystal X-ray diffraction analysis indicates that TDMeF has four polymorphs with different molecular conformations, and crystalline polymorphism is first observed in oligofluorenes. Moreover, the slight change in molecular conformation leads to form different crystal morphologies, namely, ribbon and rodlike microcrystals, in virtue of different intermolecular interactions. Finally, although both microcrystals display deep blue lasing behaviors, the rodlike microcrystal shows a threshold of 114 W/cm², which is twice times lower than that of the ribbon-like one due to the effect of molecular orientation and optical microcavity

Bimetallic Enantioselective Approach to Axially Chiral Allenes

An efficient bimetallic Zn(II)/Cu(I)-mediated asymmetric synthesis of simple axially chiral allenes from terminal alkynes and aldehydes was realized by taking advantage of the chiral amine (<i>S</i>)-α,α-diphenylprolinol <b>3</b>. This one-pot procedure is compatible with broad scopes of both terminal alkynes and aldehydes, providing axially chiral allenes in practical yields with an excellent enantioselectivity. Control experiments revealed that CuBr is responsible for the efficient formation of propargylic amine while the combination of CuBr and ZnBr₂ plays crucial roles in the amine-to-allene transformation