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On the Use of Triarylsilanols as Catalysts for Direct Amidation of Carboxylic Acids.

ABSTRACT: Triarylsilanols have been reported as the first silicon-centered molecular catalysts for direct amidation of carboxylic acids with amines as identified after a screen of silanols, silanediols, disiloxanediols, and incompletely condensed silsesquioxanes as potential homogeneous catalysts. Subsequent synthesis and testing of various electronically differentiated triarylsilanols have identified tris(p-haloaryl)silanols as more active than the parent triarylsilanol, where the bromide congener is found to be the most active. Catalyst decomposition can be observed by NMR methods, but RPKA methods reveal that product inhibition is operative, where tertiary amides are more inhibitory than secondary amides. Studies using an authentically synthesized triaryl silylester as a putative intermediate in the catalytic system enable a plausible mechanism to be proposed as supported by computationals.

SUBMITTER: Braddock DC

PROVIDER: S-EPMC10367078 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature

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On the Use of Triarylsilanols as Catalysts for Direct Amidation of Carboxylic Acids.

Braddock D Christopher DC Rowley Ben C BC Lickiss Paul D PD Fussell Steven J SJ Qamar Rabia R Pugh David D Rzepa Henry S HS White Andrew J P AJP

The Journal of organic chemistry 20230711 14

Triarylsilanols have been reported as the first silicon-centered molecular catalysts for direct amidation of carboxylic acids with amines as identified after a screen of silanols, silanediols, disiloxanediols, and incompletely condensed silsesquioxanes as potential homogeneous catalysts. Subsequent synthesis and testing of various electronically differentiated triarylsilanols have identified tris(<i>p</i>-haloaryl)silanols as more active than the parent triarylsilanol, where the bromide congener ...[more]

PMID: 37432502

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