Room temperature HFIP/Ag-promoted palladium-catalyzed C–H functionalization of benzothiazole with iodoarenes

Kapdi, Anant R.; Bhujbal, Yuvraj; Vadagaonkar, Kamlesh S.; Kori, Santosh; Kommyreddy, Saidurga Prasad; Gharpure, Santosh J.

doi:10.1039/d1cc06063e

Cited by 6 publications

(6 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additional references cited within the Supporting Information. [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]…”

Section: Supporting Informationmentioning

confidence: 99%

Ligand Combination Approach in Pd‐Catalyzed Direct C−H Arylation of Benzothiazole and Benzoxazole

Bakare,

Patil

2023

Eur J Org Chem

View full text Add to dashboard Cite

We demonstrate the use of ligand combination approach in the Pd catalyzed direct C‐H arylation of benzothiazole and benzoxazole. The combination of two ligands phenanthroline monohydrate (Phen.H2O) and triphenylphosphine (PPh3) with Pd‐catalyst have offered the best catalytic properties in the C‐H bond arylation reactions than either of two ligands employed separately in the reactions. This protocol exhibits a wide substrate scope affording C2 arylated benzothiazole and benzoxazole derivatives in excellent yields. Mechanistic studies including kinetic isotope effect (KIE), H/D exchange and competition experiments show that the C‐H bond activation of benzothiazole/benzoxazole is very facile under reaction conditions. Furthermore, different mechanistic pathways originated from the catalytically active species such as Pd(η2‐dba)L (dba = dibenzylidene acetone) and Pd(PPh3)2 were investigated using computational methods. The computational results suggest that the generation of catalytically active species from Pd2(dba)3 is endoergic process and Phen ligand can initiate this step. On the other hand, the presence of PPh3 could be crucial for the oxidative addition of aryl halides which is the rate‐determining step of the reaction.

show abstract

“…Additional references cited within the Supporting Information. [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]…”

Section: Supporting Informationmentioning

confidence: 99%

Ligand Combination Approach in Pd‐Catalyzed Direct C−H Arylation of Benzothiazole and Benzoxazole

Bakare,

Patil

2023

Eur J Org Chem

View full text Add to dashboard Cite

show abstract

“…[21] In 2022, Kori and co-workers reported palladium catalyzed direct arylation of benzothiazole with iodoarenes with Ag 2 O as the oxidant in hexafluoropropan-2-ol (HFIP). [22] Despite these considerable advances, these protocols still suffer from limitations due to several problems, such as the use of expensive, air-sensitive and toxic phosphine ligands as well as strong bases, limited substrate scope, high catalyst loading, and high temperature. In addition, most processes use homogeneous catalysts that are difficult to recover, which cause inevitable metal contamination for the product.…”

Section: Introductionmentioning

confidence: 99%

“…developed a palladium/copper cocatalytic system for direct C−H arylation [21] . In 2022, Kori and co‐workers reported palladium catalyzed direct arylation of benzothiazole with iodoarenes with Ag 2 O as the oxidant in hexafluoropropan‐2‐ol (HFIP) [22] . Despite these considerable advances, these protocols still suffer from limitations due to several problems, such as the use of expensive, air‐sensitive and toxic phosphine ligands as well as strong bases, limited substrate scope, high catalyst loading, and high temperature.…”

Section: Introductionmentioning

confidence: 99%

Design, Synthesis and Characterization of Palladium‐Functionalized Covalent Organic Framework and Its Application as Heterogeneous Catalysis for C−H Arylation of Azoles

Chen

Kang

et al. 2023

Chemistry A European J

View full text Add to dashboard Cite

A novel triazine-based covalent organic framework (TFPT-Bz COF) has been constructed by the condensation of 2,4,6-tris(5-formyl-2-pyridinoxy)-1,3,5-triazine (TFPT) and benzidine (BZ) with deep eutectic solvent (DES) as the reaction medium. After the introduction of Pd ions through strong coordination to TFPT-Bz COF matrix, the constructed TFPT-Bz COF/Pd composite exhibited excellent catalytic activity for CÀ H arylation of azoles with aryl halides in 2methyltetrahydrofuran. The protocol allows the arylation of a variety of substituted azoles with diverse aryl halides in high to excellent yield. Moreover, the TFPT-Bz COF/Pd catalyst can be recycled several times without significantly reducing its activity.

show abstract

“…Also using conditions from Table , entry 5, but with the stronger base lithium tert -butoxide, decomposition was observed, and no polymer was recovered (see the Supporting Information for details). Additionally, excluding light from the reaction did not have an effect on the molecular weight or yield (see the Supporting Information for details), although some room temperature small molecule direct arylation reactions have been shown to be light sensitive. , There is also precedent for hexafluoroisopropanol (HFIP) to facilitate room temperature small molecule C–H activation reactions . However, when HFIP was tested as a solvent in this system, no polymer was recovered (see the Supporting Information for details).…”

mentioning

confidence: 99%

“…28,29 There is also precedent for hexafluoroisopropanol (HFIP) to facilitate room temperature small molecule C−H activation reactions. 30 However, when HFIP was tested as a solvent in this system, no polymer was recovered (see the Supporting Information for details). Analysis using 1 H NMR shown in Figure 1 does not show any significant differences in the polymers synthesized using four different conditions from Tables 1 and 2.…”

mentioning

confidence: 99%

Room Temperature Synthesis of a Well-Defined Conjugated Polymer Using Direct Arylation Polymerization (DArP)

Castillo,

Thompson

2023

ACS Macro Lett.

View full text Add to dashboard Cite

While a major improvement to the sustainability of conjugated polymer synthesis, traditional direct arylation polymerization (DArP) still requires high temperatures (typically >100 °C), necessitating a significant energy input requirement. Performing DArP at reduced or ambient temperatures would represent an improvement to the sustainability of the reaction. Here we describe the first report of a well-defined conjugated polymer synthesized by DArP at room temperature. Previous efforts toward room temperature DArP relied on the use of a near-stoichiometric silver reagent, an expensive coinage metal, which makes the reaction less cost-effective and sustainable. Here, room temperature polymerizations of 3,4-ethylenedioxythiophene (EDOT) and 9,9-dioctyl-2,7-diiodofluorene were optimized and provided molar mass (M n ) up to 11 kg/mol PEDOTF, and performing the reaction at the standard ambient temperature of 25 °C provided M n up to 15 kg/mol. Model studies using other C−H monomers of varying electron density copolymerized with 9,9-dioctyl-2,7-diiodofluorene provided insight into the scope of the room temperature polymerization, suggesting that performing room temperature DArP is highly dependent on the electron richness of the C−H monomer.

show abstract

Room temperature HFIP/Ag-promoted palladium-catalyzed C–H functionalization of benzothiazole with iodoarenes

Abstract: A versatile synthetic protocol involving the room temperature direct arylation of benzothiazole with a wide variety of iodoarenes under Ag-promoted Pd-catalyzed conditions in HFIP as the reaction solvent has been...

Cited by 6 publications

References 36 publications

Ligand Combination Approach in Pd‐Catalyzed Direct C−H Arylation of Benzothiazole and Benzoxazole

Ligand Combination Approach in Pd‐Catalyzed Direct C−H Arylation of Benzothiazole and Benzoxazole

Design, Synthesis and Characterization of Palladium‐Functionalized Covalent Organic Framework and Its Application as Heterogeneous Catalysis for C−H Arylation of Azoles

Room Temperature Synthesis of a Well-Defined Conjugated Polymer Using Direct Arylation Polymerization (DArP)

Contact Info

Product

Resources

About