Prashant Gautam - Academia.edu (original) (raw)

Papers by Prashant Gautam

Research paper thumbnail of Aminophosphine Palladium Pincer-Catalyzed Carbonylative Sonogashira and Suzuki–Miyaura Cross-Coupling with High Catalytic Turnovers

ACS Omega, 2019

This work documents the first palladium pincer complex-catalyzed carbonylative Sonogashira (CS) a... more This work documents the first palladium pincer complex-catalyzed carbonylative Sonogashira (CS) and carbonylative Suzuki−Miyaura (CSM) cross-coupling. Compared to previous protocols, which employ hazardous and toxic solvents, the aminophosphine pincer complex {[C 6 H 3-2,6-(NHP{piperidinyl} 2) 2 ]Pd(Cl)} (III) catalyzes both the cross-coupling reactions in propylene carbonate, an ecofriendly and sustainable polar aprotic solvent. Advantageously, employing III allows the CS cross-coupling to be carried out at a palladium loading of 10 −4 mol % and the CSM crosscoupling to be carried out at 10 −6 mol %, thus resulting in catalytic turnovers of 10 5 and 10 7 , respectively. Relative comparison of the pincer complex with conventional palladium precursors Pd(OAc) 2 and PdCl 2 (PPh 3) 2 shows the efficiency and robustness of the pincer complex in effecting higher catalytic activity at low palladium loadings.

Research paper thumbnail of Pd/C catalyzed phenoxycarbonylation using N-formylsaccharin as a CO surrogate in propylene carbonate, a sustainable solvent

Green Chemistry, 2017

Recyclable and commercially available Pd/C catalyzes the phenoxycarbonylation reaction using N-fo... more Recyclable and commercially available Pd/C catalyzes the phenoxycarbonylation reaction using N-formylsaccharin as a CO surrogate in propylene carbonate as an environmentally benign and sustainable polar aprotic solvent under co-catalyst free, ligand free and additive free conditions.

Research paper thumbnail of Pd/C in Propylene Carbonate: A Sustainable Catalyst-Solvent System for the Carbonylative Suzuki-Miyaura Cross-Coupling Using N -Formylsaccharin as a CO Surrogate

European Journal of Organic Chemistry, 2017

This work documents the first Pd/C catalyzed carbonylative Suzuki-Miyaura cross-coupling of aryl ... more This work documents the first Pd/C catalyzed carbonylative Suzuki-Miyaura cross-coupling of aryl iodides using Nformylsaccharin as a CO surrogate. As compared to previous reaction protocols which make use of toxic and hazardous solvents, the reaction could be advantageously carried out in propylene carbonate as an environmentally benign and sustainable polar aprotic solvent. A range of biaryl ketones could be synthesized under co-catalyst free, additive free and ligand free conditions including (4-methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone, an antineoplastic belonging to the phenstatin family. Pd/C could be recycled up to five times under CO surrogacy with only a marginal decrease in catalytic activity. The reaction could also be scaled up to gram scale synthesis.

Research paper thumbnail of Oxime Palladacycle Catalyzed Carbonylative Sonogashira Cross-Coupling with High Turnovers in PEG as a Benign and Recyclable Solvent System

ChemistrySelect, 2016

Oxime palladacycles- di-μ-chlorobis [5-chloro-2-[(4- chlorophenyl)(hydroxyimino-κN) methyl] pheny... more Oxime palladacycles- di-μ-chlorobis [5-chloro-2-[(4- chlorophenyl)(hydroxyimino-κN) methyl] phenyl-κC] palladium (II) dimer (1) and di-μ-chlorobis [5-hydroxy-2-[1-(hydroxyimino-κN) ethyl] phenyl-κC] palladium (II) dimer (2) provide a phosphine free approach for the synthesis of ynones at low palladium loadings (10−5 mol%) thus resulting in catalytic turnover numbers (TONs) and turnover frequencies (TOFs) of the order of 106. Oxime palladacycle 1 shows TON 587 times and TOF 331 times higher than the best palladium catalyst reported in the literature for the carbonylative cross-coupling between 4-iodoanisole and phenylacetylene as a model reaction. The use of poly (ethylene glycol) as an environmentally benign solvent system allows the recyclability of the oxime palladacycle at low palladium loading up to four times. Further, the oxime palladacycles are advantageous in effecting higher conversion and selectivity at low palladium loadings as compared to conventional palladium precursors- Pd (OAc)2 and PdCl2(PPh3)2

Research paper thumbnail of Transition Metal-Catalyzed Carbonylative CH Bond Functionalization of Arenes and C(sp(3) )H Bond of Alkanes

Chemical record (New York, N.Y.), 2016

In this article, we present the progress made in the area of carbonylative CH functionalization,... more In this article, we present the progress made in the area of carbonylative CH functionalization, with special emphasis on arenes and alkanes. The importance of directing group assistance and CH functionalization using CO surrogates is also included. The budding development in the area of transition metal-catalyzed C(sp(3) )H activation makes us feel it necessary to file a summary on the past, as well as current, contributions and a prospective outlook on the transition metal-catalyzed carbonylative transformation of CH bonds, which is the focus of this review.

Research paper thumbnail of Aminophosphine Palladium Pincer-Catalyzed Carbonylative Sonogashira and Suzuki–Miyaura Cross-Coupling with High Catalytic Turnovers

ACS Omega, 2019

This work documents the first palladium pincer complex-catalyzed carbonylative Sonogashira (CS) a... more This work documents the first palladium pincer complex-catalyzed carbonylative Sonogashira (CS) and carbonylative Suzuki−Miyaura (CSM) cross-coupling. Compared to previous protocols, which employ hazardous and toxic solvents, the aminophosphine pincer complex {[C 6 H 3-2,6-(NHP{piperidinyl} 2) 2 ]Pd(Cl)} (III) catalyzes both the cross-coupling reactions in propylene carbonate, an ecofriendly and sustainable polar aprotic solvent. Advantageously, employing III allows the CS cross-coupling to be carried out at a palladium loading of 10 −4 mol % and the CSM crosscoupling to be carried out at 10 −6 mol %, thus resulting in catalytic turnovers of 10 5 and 10 7 , respectively. Relative comparison of the pincer complex with conventional palladium precursors Pd(OAc) 2 and PdCl 2 (PPh 3) 2 shows the efficiency and robustness of the pincer complex in effecting higher catalytic activity at low palladium loadings.

Research paper thumbnail of Pd/C catalyzed phenoxycarbonylation using N-formylsaccharin as a CO surrogate in propylene carbonate, a sustainable solvent

Green Chemistry, 2017

Recyclable and commercially available Pd/C catalyzes the phenoxycarbonylation reaction using N-fo... more Recyclable and commercially available Pd/C catalyzes the phenoxycarbonylation reaction using N-formylsaccharin as a CO surrogate in propylene carbonate as an environmentally benign and sustainable polar aprotic solvent under co-catalyst free, ligand free and additive free conditions.

Research paper thumbnail of Pd/C in Propylene Carbonate: A Sustainable Catalyst-Solvent System for the Carbonylative Suzuki-Miyaura Cross-Coupling Using N -Formylsaccharin as a CO Surrogate

European Journal of Organic Chemistry, 2017

This work documents the first Pd/C catalyzed carbonylative Suzuki-Miyaura cross-coupling of aryl ... more This work documents the first Pd/C catalyzed carbonylative Suzuki-Miyaura cross-coupling of aryl iodides using Nformylsaccharin as a CO surrogate. As compared to previous reaction protocols which make use of toxic and hazardous solvents, the reaction could be advantageously carried out in propylene carbonate as an environmentally benign and sustainable polar aprotic solvent. A range of biaryl ketones could be synthesized under co-catalyst free, additive free and ligand free conditions including (4-methoxyphenyl)(3,4,5-trimethoxyphenyl)methanone, an antineoplastic belonging to the phenstatin family. Pd/C could be recycled up to five times under CO surrogacy with only a marginal decrease in catalytic activity. The reaction could also be scaled up to gram scale synthesis.

Research paper thumbnail of Oxime Palladacycle Catalyzed Carbonylative Sonogashira Cross-Coupling with High Turnovers in PEG as a Benign and Recyclable Solvent System

ChemistrySelect, 2016

Oxime palladacycles- di-μ-chlorobis [5-chloro-2-[(4- chlorophenyl)(hydroxyimino-κN) methyl] pheny... more Oxime palladacycles- di-μ-chlorobis [5-chloro-2-[(4- chlorophenyl)(hydroxyimino-κN) methyl] phenyl-κC] palladium (II) dimer (1) and di-μ-chlorobis [5-hydroxy-2-[1-(hydroxyimino-κN) ethyl] phenyl-κC] palladium (II) dimer (2) provide a phosphine free approach for the synthesis of ynones at low palladium loadings (10−5 mol%) thus resulting in catalytic turnover numbers (TONs) and turnover frequencies (TOFs) of the order of 106. Oxime palladacycle 1 shows TON 587 times and TOF 331 times higher than the best palladium catalyst reported in the literature for the carbonylative cross-coupling between 4-iodoanisole and phenylacetylene as a model reaction. The use of poly (ethylene glycol) as an environmentally benign solvent system allows the recyclability of the oxime palladacycle at low palladium loading up to four times. Further, the oxime palladacycles are advantageous in effecting higher conversion and selectivity at low palladium loadings as compared to conventional palladium precursors- Pd (OAc)2 and PdCl2(PPh3)2

Research paper thumbnail of Transition Metal-Catalyzed Carbonylative CH Bond Functionalization of Arenes and C(sp(3) )H Bond of Alkanes

Chemical record (New York, N.Y.), 2016

In this article, we present the progress made in the area of carbonylative CH functionalization,... more In this article, we present the progress made in the area of carbonylative CH functionalization, with special emphasis on arenes and alkanes. The importance of directing group assistance and CH functionalization using CO surrogates is also included. The budding development in the area of transition metal-catalyzed C(sp(3) )H activation makes us feel it necessary to file a summary on the past, as well as current, contributions and a prospective outlook on the transition metal-catalyzed carbonylative transformation of CH bonds, which is the focus of this review.