A step-for-step main-group replica of the Fischer carbene synthesis at a borylene carbonyl.
Marcel Härterich, Alexander Matler, Rian D Dewhurst, Andreas Sachs, Kai Oppel, Andreas Stoy, Holger Braunschweig
Author Information
Marcel Härterich: Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Alexander Matler: Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Rian D Dewhurst: Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany. ORCID
Andreas Sachs: Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Kai Oppel: Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Andreas Stoy: Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Holger Braunschweig: Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany. h.braunschweig@uni-wuerzburg.de. ORCID
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)] (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.
References
Chem Sci. 2011 Jan 1;2(3):389-399
[PMID: 21743834]
Phys Rev B Condens Matter. 1988 Jan 15;37(2):785-789
[PMID: 9944570]
Angew Chem Int Ed Engl. 2021 Feb 8;60(6):2963-2968
[PMID: 33191596]
Org Biomol Chem. 2017 Feb 22;15(8):1738-1752
[PMID: 27910977]
