Bis(perchlorocatecholato)silane and Heteroleptic Bidonors: Hidden Frustrated Lewis Pairs by Ring Strain

2021 ◽  
Author(s):  
Deborah Hartmann ◽  
Sven Braner ◽  
Lutz Greb

Bis(perchlorocatecholato)silane and bidentate N,N- or N,P-heteroleptic donors form hexacoordinated complexes. Depending on the ring strain and hemilability in the adducts, Frustrated Lewis pair reactivity with aldehydes and catalytic ammonia borane...

2019 ◽  
Vol 48 (9) ◽  
pp. 2896-2899 ◽  
Author(s):  
Petra Vasko ◽  
M. Ángeles Fuentes ◽  
Jamie Hicks ◽  
Simon Aldridge

The interactions of the O–H bonds in alcohols, water and phenol with dimethylxanthene-derived frustrated Lewis pairs (FLPs) have been probed.


Synthesis ◽  
2020 ◽  
Vol 53 (01) ◽  
pp. 123-134
Author(s):  
Constantin Czekelius ◽  
Lucas Helmecke ◽  
Michael Spittler ◽  
Bernd M. Schmidt

A comparison of two catalytic, metal-free iodoperfluoro­alkylation protocols is presented. Frustrated Lewis pairs [ t Bu3P/B(C6F5)3] or phosphines/phosphites under visible light irradiation efficiently mediate the functionalization of non-activated alkenes and alkynes. A comprehensive account of the corresponding substrate scopes as well as insights into the mechanistic details of both reaction pathways are provided.


2020 ◽  
Author(s):  
Nereida Hidalgo ◽  
Juan Jose Moreno ◽  
Marina Pérez-Jiménez ◽  
Celia Maya ◽  
Joaquin López-Serrano ◽  
...  

Introducing transition metals into frustrated Lewis pair systems has attracted considerable attention in recent years. Here we report a selection of three metal-only frustrated systems based on Au(I)/Pt(0) combinations and their reactivity towards alkynes. We have inspected the activation of the simplest alkyne, namely acetylene, as well as of other internal and terminal triply bonded hydrocarbons. The gold(I) fragments are stabilized by three bulky phosphines bearing terphenyl groups. We have observed that subtle modifications on the substituents of these ligands proved critical to control the regioselectivity of acetylene activation and the product distribution resulting from C(sp)—H cleavage of phenylacetylene. A mechanistic picture based on experimental observations and computational analysis is provided. As a result of the cooperative action of the two metals of the frustrated pairs, several uncommon heterobimetallic structures have been fully characterized.


2020 ◽  
Author(s):  
Nereida Hidalgo ◽  
Juan Jose Moreno ◽  
Marina Pérez-Jiménez ◽  
Celia Maya ◽  
Joaquin López-Serrano ◽  
...  

Introducing transition metals into frustrated Lewis pair systems has attracted considerable attention in recent years. Here we report a selection of three metal-only frustrated systems based on Au(I)/Pt(0) combinations and their reactivity towards alkynes. We have inspected the activation of the simplest alkyne, namely acetylene, as well as of other internal and terminal triply bonded hydrocarbons. The gold(I) fragments are stabilized by three bulky phosphines bearing terphenyl groups. We have observed that subtle modifications on the substituents of these ligands proved critical to control the regioselectivity of acetylene activation and the product distribution resulting from C(sp)—H cleavage of phenylacetylene. A mechanistic picture based on experimental observations and computational analysis is provided. As a result of the cooperative action of the two metals of the frustrated pairs, several uncommon heterobimetallic structures have been fully characterized.


2020 ◽  
Author(s):  
Jordan N. Bentley ◽  
Ekadashi Pradhan ◽  
Tao Zeng ◽  
Christopher B. Caputo

The understanding of the mechanism by which frustrated Lewis pairs activate small molecules has been evolving with the discovery that both heterolytic and homolytic bond activation is possible. Herein we characterized a novel Lewis acidic aminoborane containing a phenothiazyl substituent and demonstrate its potential to catalytically promote the dehydrocoupling of tin hydrides. The reactivity observed implies this species promotes homolytic bond activation, however computational analysis suggests a heterolytic mechanism for this reaction. This result represents the first frustrated Lewis pair system to blur the lines between heterolytic and homolytic reactivity.


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3099 ◽  
Author(s):  
Amanda Benton ◽  
Zachariah Copeland ◽  
Stephen M. Mansell ◽  
Georgina M. Rosair ◽  
Alan J. Welch

The first example of a carborane with a catecholborolyl substituent, [1-Bcat-2-Ph-closo-1,2-C2B10H10] (1), has been prepared and characterized and shown to act as the Lewis acid component of an intermolecular frustrated Lewis pair in catalyzing a Michael addition. In combination with B(C6F5)3 the C-carboranylphosphine [1-PPh2-closo-1,2-C2B10H11] (IVa) is found to be comparable with PPh2(C6F5) in its ability to catalyze hydrosilylation, whilst the more strongly basic B-carboranylphosphine [9-PPh2-closo-1,7-C2B10H11] (V) is less effective and the very weakly basic species [μ-2,2ʹ-PPh-{1-(1ʹ-1ʹ,2ʹ-closo-C2B10H10)-1,2-closo-C2B10H10}] (IX) is completely ineffective. Base strengths are rank-ordered via measurement of the 1J 31P-77Se coupling constants of the phosphineselenides [1-SePPh2-closo-1,2-C2B10H11] (2), [9-SePPh2-closo-1,7-C2B10H11] (3), and [SePPh2(C6F5)] (4).


2014 ◽  
Vol 5 (7) ◽  
pp. 2625-2641 ◽  
Author(s):  
Douglas W. Stephan ◽  
Gerhard Erker

Frustrated Lewis pairs have been used to activate a variety of small molecules.


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