Herein, 3,5-bicyclic aryl piperidines are derivatized to generate chiral B/N FLPs. Initially, the twofold symmetric amine C6H2F2(C5H8NiPr) 1 was converted in a series of synthetic steps to the styrene-derivative C6HF2(C5H8NiPr)(CH[double bond, length as m-dash]CH2) 4. Efforts to hydroborate the vinyl fragment proved challenging as a result of the strongly basic nitrogen, although the species C6HF2(C5H8N(H)iPr)(CH2CH2B(OH)(C6F5)2) 5 was crystallographically characterized. Modification of the system was achieved by conversion of the amine C6H2F2(C5H8NH) 6 to C6HF2(C5H8NPh)(CH[double bond, length as m-dash]CH2) 9. Hydroboration of 9 with 9-BBN or HB(C6F5)2 gave C6HF2(C5H8NPh)(CH2CH2BBN) 10 or C6HF2(C5H8NPh)(CH2CH2B(C6F5)2) 11, respectively. The latter species was derivatized by complexation of PPh3 to give C6HF2(C5H8NPh)(CH2CH2B(C6F5)2)(PPh3) 12. The Lewis acidities of 10 and 11 were assessed by the Gutman-Beckett test and by computations of the FIA and GEI. While 10 did not effect HD scrambling or hydrogenation of N-phenylbenzylimine, 11 was effective in HD scrambling. Despite this, no reduction of N-t-butylbenzylimine or N-phenylbenzylimine was achieved. These data demonstrate that 10 lacks the threshold combination of Lewis acidity and basicity to activate H2, while 11 lacks the steric demands about boron to preclude classical Lewis acid-base bond formation with imine substrates.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/c8dt04070b | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Incomplete combustion yields a significant byproduct, known for its high toxicity to humans: gas phase carbon monoxide (CO). This study utilized several advanced theoretical methods to examine the factors contributing to the activation energy involved in CO capture by a frustrated Lewis pair (FLP) and to forecast the potential success of the CO capture reaction. The current theoretical findings indicate that among the four-membered-ring Group-13/N-FLP and B/Group-15-FLP molecules, only the B/N-based FLP-type molecule effectively captures CO, considering both thermodynamics and kinetics.
View Article and Find Full Text PDFUnraveling Reactivity Pathways: Dihydrogen Activation and Hydrogenation of Multiple Bonds by Pyramidalized Boron-Based Frustrated Lewis Pairs.
ChemistryOpen
April 2024
Department of Chemistry, Birla Institute of Technology Mesra, Ranchi, 835215, Jharkhand, India.
The activation of H by pyramidalized boron-based frustrated Lewis Pairs (FLPs) (B/E-FLP systems where "E" refers to N, P, As, Sb, and Bi) have been explored using density functional theory (DFT) based computational study. The activation pathway for the entire process is accurately characterized through the utilization of the activation strain model (ASM) of reactivity, shedding light on the underlying physical factors governing the process. The study also explores the hydrogenation process of multiple bonds with the help of B/N-FLP.
View Article and Find Full Text PDFNew insights into H activation by intramolecular frustrated Lewis pairs based on aminoboranes: the local electrophilicity index of boron as a suitable indicator to tune the reversibility of the process.
Chem Sci
November 2023
Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile Sergio Livingstone 1007, Independencia Santiago Chile.
A large set of intramolecular aminoborane-based FLPs was studied employing density functional theory in the H activation process to analyze how the acidity and basicity of boron and nitrogen atoms, respectively, affect the reversibility of the process. Three different linkers were employed, keeping the C-C nature in the connection between both Lewis centers: -CH-CH-, -CH[double bond, length as m-dash]CH-, and -CH-. The results show that significant differences in the Gibbs free energy of the process are found by considering all the combinations of substituents.
View Article and Find Full Text PDFTowards macrocyclic frustrated Lewis pairs.
Dalton Trans
July 2022
Department of Chemistry, University of Toronto, Toronto, 80 St George Street, Ontario M5S 3H6, Canada.
Macrocycles with and without B-N bonds were prepared from reaction of CFBH·SMe or MesBH with the 2,6-pyridinedimethanol derivatives. Both classes of macrocycle reacted with B(CF) but were unreactive to small molecules. These observations provide insights for the subsequent design of macrocyclic FLPs for multi-electron reactions.
View Article and Find Full Text PDFConstruction of frustrated Lewis pairs on carbon nitride nanosheets for catalytic hydrogenation of acetylene.
Phys Chem Chem Phys
November 2021
State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350002, China.
Here, we studied Al or B atom-doped carbon nitride (g-CN and CN) as catalysts for H activation and acetylene hydrogenation using density functional theory calculations. The Al or B could be assembled with the surface N atoms of carbon nitride to form diverse frustrated Lewis pairs (FLPs). The results show that Al-N FLPs had lower barriers of H activation in comparison with B-N FLPs.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!