Synthesis of a bifunctional boron-Lewis acid and studies on host-guest chemistry using pyridine and TMPD

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jens Rudlof ◽  
Beate Neumann ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel
Keyword(s):  
Solid State ◽  
Lewis Acid ◽  
Lewis Acids ◽  
Structure Elucidation ◽  
Decomposition Product ◽  
Functional Distance ◽  
Solid State Structures ◽  
Guest Chemistry

Abstract Based on the previously described bifunctional Lewis acid with a functional distance of the boron functions of 4.918(2) Å, the development of a further bifunctional, boron-containing Lewis acid with a wider functional distance is demonstrated. Again, a stannylated precursor was used and the Lewis-acidic boron functions were introduced by means of tin-boron exchange. The general suitability of this class of compounds for the formation of host-guest-complexes is demonstrated by NMR experiments and by solid-state structures using pyridine and TMPD (N 1,N 1,N 4,N 4-tetramethylbenzene-1,4-diamine) as Lewis basic guests. The influence of traces of moisture on the boron-containing, bifunctional Lewis acids was investigated by the structure elucidation of a decomposition product.

Tridentate Lewis-acids based on triphenylsilane

2017 ◽  
Vol 46 (5) ◽  
pp. 1645-1659 ◽  
Author(s):  
Janek Tomaschautzky ◽  
Beate Neumann ◽  
Hans-Georg Stammler ◽  
Andreas Mix ◽  
Norbert W. Mitzel
Keyword(s):  
Solid State ◽  
Lewis Acids ◽  
Building Blocks ◽  
State Structure ◽  
Solid State Structure ◽  
Guest Chemistry

Triphenylsilanes are versatile propeller-shaped building blocks and have been used for the syntheses of several novel poly-Lewis-acids. The first solid-state structure of a bisma-silatriptycene as well as investigations in host–guest chemistry of a triple alane with a threefold amine are reported.

scholarly journals “Anti-Electrostatic” Halogen Bonding

2020 ◽  
Author(s):  
Jana Holthoff ◽  
Elric Engelage ◽  
Robert Weiss ◽  
Stefan Huber
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Gas Phase ◽  
Electrostatic Potential ◽  
Lewis Acids ◽  
Halogen Bonding ◽  
Halide Complexes ◽  
Self Association ◽  
Solid State Structures ◽  
Van Der Waals Radii

Halogen bonding (XB) is often described as being driven predominantly by electrostatics, and thus adducts between <i>anionic</i> XB donors (halogen-based Lewis acids) and anions seem counter­intuitive. Such “anti-electrostatic” XBs have been predicted theoretically, but there are currently no experimental examples based on organic XB donors. Herein, we report the synthesis of two negatively charged organoiodine derivatives, which were subsequently investigated towards their ability to form “anti-electrostatic” XBs with anions. Even though the electrostatic potential is universally negative across the surface of both compounds, DFT calculations indicate kinetic stabilization of their halide complexes in the gas phase and particularly in solution. Experimentally, self-association of the anionic XB donors was observed in solid-state structures, resulting in dimers, trimers and infinite chains. In addition, co-crystals with halides were obtained which featured XB adducts between two or even three anions. The bond-lengths of all observed interactions are 14-21% shorter than sum of the van-der-Waals radii.

scholarly journals “Anti-Electrostatic” Halogen Bonding

2020 ◽  
Author(s):  
Jana Holthoff ◽  
Elric Engelage ◽  
Robert Weiss ◽  
Stefan Huber
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Gas Phase ◽  
Electrostatic Potential ◽  
Lewis Acids ◽  
Halogen Bonding ◽  
Halide Complexes ◽  
Self Association ◽  
Solid State Structures ◽  
Van Der Waals Radii

Halogen bonding (XB) is often described as being driven predominantly by electrostatics, and thus adducts between <i>anionic</i> XB donors (halogen-based Lewis acids) and anions seem counter­intuitive. Such “anti-electrostatic” XBs have been predicted theoretically, but there are currently no experimental examples based on organic XB donors. Herein, we report the synthesis of two negatively charged organoiodine derivatives, which were subsequently investigated towards their ability to form “anti-electrostatic” XBs with anions. Even though the electrostatic potential is universally negative across the surface of both compounds, DFT calculations indicate kinetic stabilization of their halide complexes in the gas phase and particularly in solution. Experimentally, self-association of the anionic XB donors was observed in solid-state structures, resulting in dimers, trimers and infinite chains. In addition, co-crystals with halides were obtained which featured XB adducts between two or even three anions. The bond-lengths of all observed interactions are 14-21% shorter than sum of the van-der-Waals radii.

Synthesis and solid state structures of macromolecular cylindrical brushes with varying side chain length

Polymer ◽  
2004 ◽  
Vol 45 (12) ◽  
pp. 4009-4015 ◽  
Author(s):  
Bin Zhang ◽  
Shanju Zhang ◽  
Lidia Okrasa ◽  
Tadeusz Pakula ◽  
Tim Stephan ◽  
...  
Keyword(s):  
Solid State ◽  
Chain Length ◽  
Side Chain ◽  
Side Chain Length ◽  
Solid State Structures

Lewis Acid-Promoted Suzuki Reaction using Palladium Chloride Anchored on a Polymer as a Catalyst

2008 ◽  
Vol 61 (8) ◽  
pp. 610 ◽  
Author(s):  
Guozhi Fan ◽  
Hanjun Zhang ◽  
Siqing Cheng ◽  
Zhandong Ren ◽  
Zhijun Hu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Lewis Acids ◽  
Heterogeneous Catalysts ◽  
Suzuki Reaction ◽  
Cross Coupling ◽  
Palladium Chloride ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Recoverable Catalyst

Palladium chloride anchored on polystyrene modified by 5-amino-1,10-phenanthroline was prepared and used as an efficient recoverable catalyst for Suzuki cross-coupling reactions. The heterogeneous catalysts can be easily separated from the reaction mixture and reused for five cycles without significant Pd leaching and loss of catalytic activity. Rate enhancement in the Suzuki reaction by Lewis acids was also studied.

Synthesis of pyrrolo[1,2-a]naphthyridines by Lewis acid mediated cycloisomerization

2017 ◽  
Vol 15 (15) ◽  
pp. 3216-3231 ◽  
Author(s):  
Anika Flader ◽  
Silvio Parpart ◽  
Peter Ehlers ◽  
Peter Langer
Keyword(s):  
Lewis Acid ◽  
Lewis Acids

Functionalized pyrrolo[1,2-a]naphthyridines were synthesized by application of PtCl2 and Bi(OTf)3 as simple Lewis acids in a cycloisomerization reaction.

Sign in / Sign up

Export Citation Format

Share Document