On the Reactivity of the Carba‐closo‐dodecaborate Anion with the Trityl Cation

Abstract

Abstract:In 1994 Reed and co-workers reported a variety of trityl salts with various functionalized icosahedral carborane anions. However, it was mentioned that the parent carba-closododecaborate anion [HCB 11 H 11 ] -underwent an unidentified chemical reaction with the trityl cation as the ion pair formed in solution. In this communication, we have reexamined this reaction and identified the reaction as classical electrophilic

Strongly Coordinating Ligands To Form Weakly Coordinating Yet Functional Organometallic Anions

“…However, on the basis of characteristic aryl resonances and high-resolution mass spectrometry, we are able to tentatively assign some of the decomposition products as species arising from the electrophilic arylation of the carborane cage with the trityl cation, a new reaction that we recently reported. 23 In addition, we were able to inconsistently isolate in pure form an extraordinary cyclometalated Au(III) boryl NHC chelate, 4, which was unambiguously identified by multinuclear NMR and a singlecrystal X-ray diffraction study (Figure 2, bottom right). Trans to the boryl ligand, a B−H agostic "like" interaction weakly interacts with a Au orbital.…”

“…Dissolving 3­[CPh 3 + ] in a solvent such as dichloromethane, chloroform, or F–C 6 H 5 rapidly leads to a complex mixture of products, which are extremely challenging to separate. However, on the basis of characteristic aryl resonances and high-resolution mass spectrometry, we are able to tentatively assign some of the decomposition products as species arising from the electrophilic arylation of the carborane cage with the trityl cation, a new reaction that we recently reported . In addition, we were able to inconsistently isolate in pure form an extraordinary cyclometalated Au­(III) boryl NHC chelate, 4 , which was unambiguously identified by multinuclear NMR and a single-crystal X-ray diffraction study (Figure , bottom right).…”

“…This is important because if practical synthesis methods used to cleanly afford species such as 4 can be developed, then this would lead to prototypical Au­(III) systems for exploring classical d 8 reaction chemistry. Although we are not sure of the mechanism of the formation of 4 , we can say that we do observe tri­phenyl­methane and electrophilic arylation where trityl liberates a proton . Thus far, all attempts to induce this reaction via hydride abstraction from 3 with external trityl or protic acids have been unsuccessful.…”

A fast and simple B–C bond formation in metallacarboranes avoiding halometallacarboranes and transition metal catalysts

“…Lavallo also found isomeric non-separable mixtures of meta-and paraupon the reaction of TrBr with [CB 11 H 12 ] − in FC 6 H 5 . 13 Reactions via carbocation generation in situ Just to explore if this method could have a wider application without the need to use preformed stable electrophiles, we have attempted to produce carbocations in situ. One way of producing carbocations is by mixing halogenated reagents RX with soluble silver salts, resulting in the precipitation of the AgX salt and the formation of the carbocation.…”

One‐pot Annulation for Biaryl‐fused Monocarba‐closo‐dodecaborate through Aromatic B−H Bond Disconnection

“…[8] Lavallo, Kefalidis and co-workers reported the unique reactivity of aP d 0 complex supported by monoanionic C1-carboranyl phosphine, which partially afforded a2 -B-cyclometalated Pd II complex during the fast oxidativea ddition of chlorobenzene. [9] Given the unique properties and potentialapplicationsof2,introduction of an aryl group on the C1-carborane cage, [10] in particular at the ortho-boron vertices,i so fg reat significance. Our initial focus on an intramolecular strategy based on 1-C-arylated derivatives 2 was unsuccessful because the stepwise functionalization by 4 failed, likely due to steric hindrance (Scheme 1b).…”