Intramolecular cooperativity in frustrated Lewis pairs

2016 ◽  
Vol 52 (64) ◽  
pp. 9949-9952 ◽  
Author(s):  
Leif A. Körte ◽  
Sebastian Blomeyer ◽  
Shari Heidemeyer ◽  
Andreas Mix ◽  
Beate Neumann ◽  
...  

The doubly Lewis-acid functionalised aniline PhN[(CH2)3B(C6F5)2]2 features two competing boron functions in fast exchange for binding to the central Lewis base. In contrast to the mono acid-functionalised PhMeN[(CH2)3B(C6F5)2], it is an active frustrated Lewis pair.

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).


Author(s):  
Frédéric-Georges Fontaine ◽  
Douglas W. Stephan

In this concept article, we consider the notion of ‘frustrated Lewis pairs’ (FLPs). While the original use of the term referred to steric inhibition of dative bond formation in a Lewis pair, work in the intervening decade demonstrates the limitation of this simplistic view. Analogies to known transition metal chemistry and the applications in other areas of chemistry are considered. In the light of these findings, we present reflections on the criteria for a definition of the term ‘frustrated Lewis pair’. Segregation of the Lewis acid and base and the kinetic nature of FLP reactivity are discussed. We are led to the conclusion that, while an all-inclusive definition of FLP is challenging, the notion of ‘FLP chemistry’ is more readily recognized. This article is part of the themed issue ‘Frustrated Lewis pair chemistry’.


2012 ◽  
Vol 84 (11) ◽  
pp. 2203-2217 ◽  
Author(s):  
Gerhard Erker

The chemistry of some reactive frustrated Lewis pairs (FLPs) is reported. This includes intramolecular P/B and N/B FLPs, some of which were used as catalysts for the hydrogenation of electron-rich olefin substrates. Some advanced intermolecular FLPs are reported, which includes systems derived from very bulky alkenyl boranes obtained from 1,1-carboboration reactions of 1-alkynes with tris(pentafluorophenyl)borane. Some such systems activate dihydrogen and transfer the resulting proton/hydride pair even to some electron-poor alkynes. Eventually, we report on the reaction of our intramolecular ethylene-bridged P/B FLP with nitric oxide (NO). N,B-addition of the P-Lewis base/B-Lewis acid combination is observed to form a new type of a persistent aminoxyl radical. Some of the chemistry of the new FLP-NO radicals is presented and discussed.


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...


2016 ◽  
Vol 6 (3) ◽  
pp. 882-889 ◽  
Author(s):  
Kai C. Szeto ◽  
Wissam Sahyoun ◽  
Nicolas Merle ◽  
Jessica Llop Castelbou ◽  
Nicolas Popoff ◽  
...  

Supported Lewis acid/base systems based have been prepared and characterized.


Synthesis ◽  
2021 ◽  
Author(s):  
Felix Wech ◽  
Urs Gellrich

In recent years, borane-based frustrated Lewis pairs proved to be efficient hydrogenation catalysts and became an alternative to transition metal-based systems. The hydrogen activation by classic FLPs leads to a protonated Lewis base and a borohydride. Consequently, hydrogenations catalyzed by classic FLPs consist of stepwise hydride transfer reactions and protonations (or vice versa). More recently, systems that operate via an initial hydroboration have allowed extending the substrate scope for FLP catalyzed hydrogenations. Within this review, hydrogenations of organic substrates catalyzed by borane-based frustrated Lewis pairs are discussed. Emphasis is given to the mechanistic aspects of these catalytic reactions.


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 ◽  
Vol 132 (11) ◽  
pp. 4528-4534 ◽  
Author(s):  
Bochao Gao ◽  
Xiangqing Feng ◽  
Wei Meng ◽  
Haifeng Du

Tetrahedron ◽  
2019 ◽  
Vol 75 (5) ◽  
pp. 571-579 ◽  
Author(s):  
Jennifer Möricke ◽  
Florian Rehwinkel ◽  
Tobias Danelzik ◽  
Constantin G. Daniliuc ◽  
Birgit Wibbeling ◽  
...  

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