Reactivity of a Terminal Chromium Borylene Complex towards Olefins: Insertion of a Borylene into a CH Bond

Abstract

Borylene insertion: Irradiation of the terminal borylene complex [(OC)5CrBN(SiMe3)2] at room temperature in the presence of 3,3‐dimethyl‐1‐butene leads to insertion of the aminoborylene moiety into the olefinic CH bond and formation of a vinylborane complex (see structure).

Formation and Reactivity of Electron‐Precise B−B Single and Multiple Bonds

“…Thel ongest classical oligoboranes isolated to date,l inear B 6 (NMe 2 ) 8 [19] and cyclic B 6 (NR 2 ) 6 (R = Me,E t), [17,23] are only formed as negligible by-products of otherwise unselective reductive coupling reactions.W hile the exact mechanism of these reactions is still unclear, the generation of highly reactive boryl radical and/or borylene intermediates tends to lead to unwanted side-reactions,such as radical hydrogen abstraction from solvent or borylene insertion into CÀHa nd CÀC bonds, [24] as observed, for example,byP ower and co-workers in their attempt to synthesize doubly bonded diborenes stabilized by bulky terphenyl groups (Scheme 2). [26] Ther eaction, yielding non-classical nido-metallaborane, 2,w ith aB ÀB bond length of 1.695 (7) ,was postulated to proceed via the dimerization of am ononuclear terminal borylene intermediate. [7,25] These new synthetic methods,a sw ell as early forays into the reactivity of BÀB multiple bonds,will be discussed in this Review.…”

Computational Study of van der Waals Complexes between Borylenes and Hydrocarbons

“…Free borylenes could not be isolated, although they can be stabilized either by cyclic alkyl amino carbenes (CAAC)9 or by transition‐metal centers 10. Borylene ligands can also be transferred photochemically from transition‐metal complexes to unsaturated hydrocarbons, which can result in borirene formation11 or CH insertion in the case of olefins 12…”

From Borane to Borylene without Reduction: Ambiphilic Behavior of a Monovalent Silylisonitrile Boron Species

“…[3] Our own group later isolated an anionic dimetalloborylene complex [4] and an N-heterocyclic carbene (NHC) stabilized borole anion (II), [5] while Curran and co-workers succeeded in trapping transient {BH 2 } À with av ariety of electrophiles. [6] Making use of the excellent s-donor and p-acceptor properties of cyclic (alkyl)(amino)carbenes (cAACs) [7] and oxazol-2-ylidene ligands,t he groups of Bertrand and Kinjo reported the first examples of metal-free,n ucleophilic monovalent boron compounds,s uch as compound III.…”