Transition‐Metal‐Like Catalysis with a Main‐Group Element: Bismuth‐Catalyzed C−F Coupling of Aryl Boronic Esters

2020 ◽  
Vol 59 (22) ◽  
pp. 8328-8330 ◽  
Author(s):  
Daniel Janssen‐Müller ◽  
Martin Oestreich
2019 ◽  
Author(s):  
Oriol Planas ◽  
Feng Wang ◽  
Markus Leutzsch ◽  
Josep Cornella

The ability of bismuth to maneuver between different oxidation states in a catalytic redox cycle, mimicking the canonical organometallic steps associated to a transition metal, is an elusive and unprecedented approach in the field of homogeneous catalysis. Herein we present a catalytic protocol based on bismuth, a benign and sustainable main-group element, capable of performing every organometallic step in the context of oxidative fluorination of boron compounds; a territory reserved to transition metals. A rational ligand design featuring hypervalent coordination together with a mechanistic understanding of the fundamental steps, permitted a catalytic fluorination protocol based on a Bi(III)/Bi(V) redox couple, which represents a unique example where a main-group element is capable of outperforming its transition metal counterparts.<br>A main text and supplementary material have been attached as pdf files containing all the methodology, techniques and characterization of the compounds reported.<br>


Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 286
Author(s):  
Edward R.T. Tiekink

A search of the Cambridge Structural Database was conducted for pyridyl-substituted dithiocarbamate ligands. This entailed molecules containing both an NCS2− residue and pyridyl group(s), in order to study their complexation behavior in their transition metal and main group element crystals, i.e., d- and p-block elements. In all, 73 different structures were identified with 30 distinct dithiocarbamate ligands. As a general observation, the structures of the transition metal dithiocarbamates resembled those of their non-pyridyl derivatives, there being no role for the pyridyl-nitrogen atom in coordination. While the same is true for many main group element dithiocarbamates, a far greater role for coordination of the pyridyl-nitrogen atoms was evident, in particular, for the heavier elements. The participation of pyridyl-nitrogen in coordination often leads to the formation of dimeric aggregates but also one-dimensional chains and two-dimensional arrays. Capricious behaviour in closely related species that adopted very different architectures is noted. Sometimes different molecules comprising the asymmetric-unit of a crystal behave differently. The foregoing suggests this to be an area in early development and is a fertile avenue for systematic research for probing further crystallization outcomes and for the rational generation of supramolecular architectures.


2017 ◽  
Vol 56 (41) ◽  
pp. 12741-12745 ◽  
Author(s):  
Gengwen Tan ◽  
Jing Li ◽  
Li Zhang ◽  
Chao Chen ◽  
Yue Zhao ◽  
...  

Inorganics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 7
Author(s):  
See Mun Lee ◽  
Edward R. T. Tiekink

An overview is presented of the crystal structures of transition metal, main group element, and lanthanide compounds containing poly-functional dithiocarbamate ligands, namely species containing two or more connected NCS2− residues. In all, there are 40 different ligands of this type that have been characterised crystallographically in their heavy-element compounds with up to six NCS2− residues; all are bridging. In most cases, the resulting aggregates are zero-dimensional, often di-nuclear, but aggregates of up to 36 metal (gold) atoms are noted. There are smaller numbers of one-, two-, and three-dimensional architectures sustained by poly-functional dithiocarbamate ligands in their respective crystals. The survey highlights the opportunities afforded by this generally under-studied class of ligand.


1999 ◽  
Vol 54 (6) ◽  
pp. 751-756 ◽  
Author(s):  
Karin Brüning ◽  
Bettina Lühmann ◽  
Heinrich Lang

The preparation of the first and second generation carbosiloxane dendrimers Si[OCH2- CH2CH2 SiMe(OCH2C=CH)2]4 (3) and Si{OCH2H2CH2SiMe[OCH2CH2CH2SiMe(OCH2 - C=CH)2]2}4 (5) by the reaction o f Si(OCH2CH2CH2SiMeCl2)4 (1) or Si[OCH2CH2CH2SiMe- (OCH2CH2CH2SiMeCl2)2]4 (4) with HOCH2C =CH (2) in the presence o f NEt3 is described. Dendrimers 3 and 5 contain propargyloxy units as terminal groups, which can be transferred to Co2((CO)8 (6) to give the hexacarbonyldicobalt functionalized dendritic molecules Si{OCH2CH2CH2[(η-OCH2C=CH)CO2(CO)6]2}4 (7) and Si{OCH2CH2CH2SiMe-(OCH2CH2CH2SiMe[(η-OCH2C=CH)CO2(CO)6]2)2}4 (8). All compounds were characterized by elemental analyses, spectroscopic studies (IR,1H-, 13C{1H }-, 29Si{1H} NMR) as well as GPC investigations


2019 ◽  
Author(s):  
Oriol Planas ◽  
Feng Wang ◽  
Markus Leutzsch ◽  
Josep Cornella

The ability of bismuth to maneuver between different oxidation states in a catalytic redox cycle, mimicking the canonical organometallic steps associated to a transition metal, is an elusive and unprecedented approach in the field of homogeneous catalysis. Herein we present a catalytic protocol based on bismuth, a benign and sustainable main-group element, capable of performing every organometallic step in the context of oxidative fluorination of boron compounds; a territory reserved to transition metals. A rational ligand design featuring hypervalent coordination together with a mechanistic understanding of the fundamental steps, permitted a catalytic fluorination protocol based on a Bi(III)/Bi(V) redox couple, which represents a unique example where a main-group element is capable of outperforming its transition metal counterparts.<br>A main text and supplementary material have been attached as pdf files containing all the methodology, techniques and characterization of the compounds reported.<br>


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