TY  - JOUR
A1  - Härterich, Marcel
A1  - Matler, Alexander
A1  - Dewhurst, Rian D.
A1  - Sachs, Andreas
A1  - Oppel, Kai
A1  - Stoy, Andreas
A1  - Braunschweig, Holger
T1  - A step-for-step main-group replica of the Fischer carbene synthesis at a borylene carbonyl
JF  - Nature Communications
N2  - The Fischer carbene synthesis, involving the conversion of a transition metal (TM)-bound CO ligand to a carbene ligand of the form [=C(OR’)R] (R, R’ = organyl groups), is one of the seminal reactions in the history of organometallic chemistry. Carbonyl complexes of p-block elements, of the form [E(CO)n] (E = main-group fragment), are much less abundant than their TM cousins; this scarcity and the general instability of low-valent p-block species means that replicating the historical reactions of TM carbonyls is often very difficult. Here we present a step-for-step replica of the Fischer carbene synthesis at a borylene carbonyl involving nucleophilic attack at the carbonyl carbon followed by electrophilic quenching at the resultant acylate oxygen atom. These reactions provide borylene acylates and alkoxy-/silyloxy-substituted alkylideneboranes, main-group analogues of the archetypal transition metal acylate and Fischer carbene families, respectively. When either the incoming electrophile or the boron center has a modest steric profile, the electrophile instead attacks at the boron atom, leading to carbene-stabilized acylboranes – boron analogues of the well-known transition metal acyl complexes. These results constitute faithful main-group replicas of a number of historical organometallic processes and pave the way to further advances in the field of main-group metallomimetics.
KW  - chemical bonding
KW  - ligands
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357270
VL  - 14
ER  - 
TY  - JOUR
A1  - Gotru, Sanjeev Kiran
A1  - van Geffen, Johanna P.
A1  - Nagy, Magdolna
A1  - Mammadova-Bach, Elmina
A1  - Eilenberger, Julia
A1  - Volz, Julia
A1  - Manukjan, Georgi
A1  - Schulze, Harald
A1  - Wagner, Leonard
A1  - Eber, Stefan
A1  - Schambeck, Christian
A1  - Deppermann, Carsten
A1  - Brouns, Sanne
A1  - Nurden, Paquita
A1  - Greinacher, Andreas
A1  - Sachs, Ulrich
A1  - Nieswandt, Bernhard
A1  - Hermanns, Heike M.
A1  - Heemskerk, Johan W. M.
A1  - Braun, Attila
T1  - Defective Zn2+ homeostasis in mouse and human platelets with α- and δ-storage pool diseases
JF  - Scientific Reports
N2  - Zinc (Zn2+) can modulate platelet and coagulation activation pathways, including fibrin formation. Here, we studied the (patho)physiological consequences of abnormal platelet Zn2+ storage and release. To visualize Zn2+ storage in human and mouse platelets, the Zn2+ specific fluorescent dye FluoZin3 was used. In resting platelets, the dye transiently accumulated into distinct cytosolic puncta, which were lost upon platelet activation. Platelets isolated from Unc13d−/− mice, characterized by combined defects of α/δ granular release, showed a markedly impaired Zn2+ release upon activation. Platelets from Nbeal2−/− mice mimicking Gray platelet syndrome (GPS), characterized by primarily loss of the α-granule content, had strongly reduced Zn2+ levels, which was also confirmed in primary megakaryocytes. In human platelets isolated from patients with GPS, Hermansky-Pudlak Syndrome (HPS) and Storage Pool Disease (SPD) altered Zn2+ homeostasis was detected. In turbidity and flow based assays, platelet-dependent fibrin formation was impaired in both Nbeal2−/− and Unc13d−/− mice, and the impairment could be partially restored by extracellular Zn2+. Altogether, we conclude that the release of ionic Zn2+ store from secretory granules upon platelet activation contributes to the procoagulant role of Zn2+ in platelet-dependent fibrin formation.
KW  - coagulation system
KW  - metals
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227455
VL  - 9
ER  -