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Steric effects

About: Steric effects is a research topic. Over the lifetime, 16112 publications have been published within this topic receiving 319615 citations. The topic is also known as: steric hindrance.


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Journal ArticleDOI
TL;DR: The X-ray crystal packing analyses of the sterically encumbered halogen-substituted benzene carboxylic acids 1-4 reveal a novel and unprecedented crystal packing in that the association of the carboxyl groups through O-H...O bonds results in the generation of a helix along the 41-screw axis.
Abstract: The X-ray crystal packing analyses of the sterically encumbered halogen-substituted benzene carboxylic acids 1−4 reveal a novel and unprecedented crystal packing in that the association of the carboxyl groups through O−H···O bonds results in the generation of a helix along the 41-screw axis. Such an organization of the acids is shown convincingly to be a result of the close packing, which exploits the weaker X···X and C−H···X interactions in conjunction with the stronger O−H···O hydrogen bonds. In contrast, the chloro- and bromo-substituted durene carboxylic acids 6 and 7 exhibit a pattern that is akin to tape/ribbon involving the centrosymmetric-dimer motif and X···X short intermolecular interactions. The structural investigations demonstrate the ability of the weaker interactions in modifying the supposedly “robust” centrosymmetric-dimer motif of the carboxyl groups in a decisive manner.

109 citations

Journal ArticleDOI
TL;DR: In this article, the role of steric bulk and π electron release within the ERn substituent in generating tractable borylene complexes has been probed, as has the nature of the counterion.

108 citations

Journal ArticleDOI
TL;DR: Application of these phosphine ligands in palladium-catalyzed C-N bond forming reactions revealed the crucial roles of the steric bulk of the substituents on the phosphorus atom governing the catalytic activity.
Abstract: A series of 2-dialkylphosphino-2'-alkoxy-1,1'-binaphthyl ligands (6a-c and 8a-c) have been prepared conveniently by a lithium-initiated ring-opening reaction of dinaphthofuran, followed by selective phosphorylation. These compounds displayed a remarkable air and moisture stability, both in solid form and in solution. Application of these phosphine ligands in palladium-catalyzed C-N bond forming reactions revealed the crucial roles of the steric bulk of the substituents on the phosphorus atom governing the catalytic activity. Specifically, 2-di-tert-butylphosphino-2'-isopropoxy-1,1'-binaphthyl (8b) proved to be the most effective for the aminations of aryl halides with primary amines, while the less bulky 2-dicyclohexyl-2'-methoxy-1,1'-binaphthyl (6a) was more effective for the aminations with secondary amines. The steric and electronic effects of the ligands were analyzed to account for these observations.

108 citations

Journal ArticleDOI
TL;DR: A generally highly efficient and broadly applicable synthesis of carboxymethyl ketones from readily available carboxylic acids and terminal alkynes is developed under exceptionally mild reaction conditions.
Abstract: Steric Bulk or Conformation Control? Optimization of P,N-bidentate ligands reveals the importance of conformation control in the development of highly efficient intermolecular trapping of reactive α-oxo gold carbene intermediates. While a pendant piperidine ring offers suitable steric bulk, fixing its conformation to provide better shielding to the highly electrophilic carbene center turned out to be crucial for the excellent reaction efficiency. A generally highly efficient and broadly applicable synthesis of carboxymethyl ketones from readily available carboxylic acids and terminal alkynes is developed under exceptionally mild reaction conditions.

108 citations

Journal ArticleDOI
TL;DR: In this article, it was shown that with a suitably bulky bidentate ligand, three-coordinate, high-spin alkyl complexes of iron(II) are stable.

108 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023942
20221,917
2021346
2020292
2019296
2018307