Organozinc compounds containing sp, sp2, and sp3 C–Zn moieties undergo transmetalation with pinacolborane (HBPin) to produce Zn–H species organoboronate esters (RBPin). This Zn–C/H–B metathesis step is key enabling zinc-catalyzed borylation reactions, it used in this work develop both terminal alkyne C–H internal hydroboration. These two conversions can be combined one pot achieve the conversion of alkynes 1,1-diborylated alkenes without isolation sensitive (to protodeboronation) alkynyl...

Indoles are privileged heterocycles found in many biologically active pharmaceuticals and natural products. However, the selective functionalization of benzenoid moiety indoles preference to more reactive pyrrolic unit is a significant challenge. Herein we report that N-acyl directing groups enable C7-selective C-H borylation using just BBr

Helicenes are chiral polycyclic aromatic hydrocarbons (PAHs) of significant interest,

Abstract Edging closer towards developing air and moisture compatible polar organometallic chemistry, the chemoselective ultrafast addition of a range aryllithium reagents to nitriles has been accomplished by using glycerol as solvent, at ambient temperature in presence air, establishing novel sustainable access aromatic ketones. Addition reactions occur heterogeneously (“on conditions”), where lack solubility ability latter form strong intermolecular hydrogen bonds seem key favouring...

Using two alternative methodologies, new light has been shed on the stability and rational formation of abnormal NHC–gallium complexes.

Abstract A series of heteroleptic monoamido‐monohydrido‐dialkylaluminate complexes general formula [ i Bu 2 AlTMPHLi⋅donor] were synthesized and characterised in solution the solid state. Applying these catalytic hydroboration reactions with representative aldehydes ketones reveals that all are competent, however a definite donor substituent effect is discernible. The bifunctional nature also probed by assessing their performance metallation triazole phenylacetylene addition across pyrazine....

The synthesis of 1,1,1-triborylalkanes from terminal alkynes and pinacolborane (HBPin) is reported. This transformation proceeds via initial Zn-catalyzed alkyne C–H borylation, which can be achieved using a NacNacZnH complex. Combinations NacNacZn-alkynyl formed zincation HBPin exist in equilibrium with the alkynyl-BPin NacNacZnH. consumption by irreversible reaction evolving H2 essential for driving borylation to completion. compounds undergo hydroboration catalyzed Zn–H complexes at raised...

The synthesis of a range brominated-B_n-containing (<italic>n</italic> = 1, 2) polycyclic aromatic hydrocarbons (PAHs) is achieved simply by reacting BBr₃ with appropriately substituted alkynes <italic>via</italic> bromoboration/electrophilic C–H borylation sequence.

Amide directed C-H borylation using ≥two equiv. of BBr3 forms borenium cations containing a R2N(R')C[double bond, length as m-dash]O→B(Ar)Br unit which has significant Lewis acidity at the carbonyl carbon. This enables reduction amide to an amine hydrosilanes. approach can be applied sequentially in one-pot electrophilic borylation-reduction process, for phenyl-acetylamides generates ortho borylated compounds that directly oxidised 2-(2-aminoethyl)-phenol. Other substrates amenable sequence...

Fluoroaromatic scaffolds pose a challenge to lithiation due low stability of lithiated intermediates. Here we apply trans-metal-trapping (TMT) series key fluorinated aromatics. In TMT, LiTMP performs the metalation, while an organometallic trap intercepts emergent carbanion. This study contrasts trapping abilities iBu2 AlTMP and Ga(CH2 SiMe3 )3 , structurally mapping their TMT reactions probing relative stabilities metalated fluoroaromatic intermediates by NMR studies. Results show installed...

Abstract Pyrazabole ( 1 ) is a readily accessible diboron compound that can be transformed into ditopic electrophiles. In (and derivatives), the B⋅⋅⋅B separation ca. 3 Å, appropriate for one boron centre bonding to N and C7 of indoles indolines. This suitable enables double E−H (E=N/C) functionalisation Specifically, activation with HNTf 2 generates an electrophile transforms N−H indolines N/C7‐diborylated indolines, borylation directing subsequent C7−H borylation. Indole reduction indoline...

This study establishes a new trans-metal-trapping (TMT) procedure based on mixture of LiTMP (the base) and tris(trimethylsilylmethyl)gallium [Ga(CH2 SiMe3 )3 , GaR3 ] trap) that, operating in tandem manner, is effective for the regioselective deprotonation sensitive diazines hydrocarbon solution, as illustrated through reactions pyrazine, pyridazine, pyrimidine, well N-S heterocycle benzothiazole. The metallo-activated complexes all these compounds were isolated structurally defined.

Merging two topical themes in main-group chemistry, namely, cooperative bimetallics and frustrated-Lewis-pair (FLP) activity, this Forum Article focuses on the cooperativity-induced outcomes observed when tris(alkyl)gallium compound GaR3 (R = CH2SiMe3) is paired with lithium amide LiTMP (TMP 2,2,6,6-tetramethylpiperidide) or sterically hindered N-heterocyclic carbene (NHC) 1,3-bis(tert-butyl)imidazol-2-ylidene (ItBu). When some previously published work are drawn together new results, unique...

This study explores the synthetic utility of homo(aryl) lithum zincate reagents [LiZnPh3] (2) and [Li2ZnPh4] (3), made by cocomplexation variable amounts their monometallic components LiPh ZnPh2 (1), as chemoselective nucleophilic arylating reagents. Lithium zincates 2 3 were both characterized multinuclear (1H, 13C, 7Li) NMR spectroscopy, in case 2, a classical reagent heterobimetallic chemistry, molecular structure its OnBu2 solvate [LiZnPh3(OnBu2)2] 2·2OBu2 has been established X-ray...

Defined as the transfer of ligands from one metal to another, transmetallation is a common reaction in organometallic chemistry. Its chemical celebrity stems its role important catalytic cycles cross-coupling reactions such those Negishi, Sonogashira, Stille, or Suzuki. This article focuses on trans-metal-trapping (TMT), which could be construed partially complete transmetallations. On mixing two distinct compounds, for example lithium with aluminium gallium, metals meet crossover...

Abstract This study reports the use of trisalkylgallium GaR 3 (R=CH 2 SiMe ), containing sterically demanding monosilyl groups, as an effective Lewis‐acid component for frustrated Lewis pair activation carbonyl compounds, when combined with bulky N‐heterocyclic carbene 1,3‐bis( tert ‐butyl)imidazol‐2‐ylidene (I t Bu) or ‐butyl)imidazolin‐2‐ylidene (SI Bu). The reduction aldehydes can be achieved by insertion into C=O functionality at C2 (so‐called normal) position affording zwitterionic...

Bromo-functionalized B1-polycyclic aromatic hydrocarbons (PAHs) with LUMOs of less than -3.0 eV were synthesized and used in cross-couplings to form donor-acceptor materials. These materials spanned a range S1 energies, number showing thermally activated delayed fluorescence significant emission the near-infrared region spectrum. B1-PAHs represent useful family acceptors that can be readily functionalized.

N-Heterocyclic carbenes (NHCs) have become indispensable ligands across a broad swathe of the synthetic and catalytic landscape, not in small part due to their ease electronic steric tunability. One latest additions this important family are anionic NHCs, which valuable precursors access abnormal NHC complexes as well shown great potential for further functionalisation. Deprotonative metallation has emerged one most versatile methodologies where judicious choice reaction conditions...

Abstract Pairing lithium and manganese(II) to form manganate [Li 2 Mn(CH SiMe 3 ) 4 ] enables the efficient direct Mn–I exchange of aryliodides, affording transient (aryl)lithium intermediates which in turn undergo spontaneous C−C homocoupling at room temperature furnish symmetrical (bis)aryls good yields under mild reaction conditions. The combination EPR with X‐ray crystallographic studies has revealed mixed Li/Mn constitution organometallic involved these reactions, including step had...

Despite the general high fluorophilicity of boron, organoboranes such as BEt3 and 3,5-(CF3)2C6H3-BPin are shown herein for first time, to our knowledge, be effective (solid solution) phase-transfer catalysts fluorination certain organohalides with CsF. Significant (up 30% e.e.) chiral induction during nucleophilic form β-fluoroamines using oxazaborolidine (pre)catalysts CsF also can achieved. Screening different boranes revealed a correlation between calculated fluoride affinity borane...

Abstract Fluoroaromatic scaffolds pose a challenge to lithiation due low stability of lithiated intermediates. Here we apply trans‐metal‐trapping (TMT) series key fluorinated aromatics. In TMT, LiTMP performs the metalation, while an organometallic trap intercepts emergent carbanion. This study contrasts trapping abilities i Bu 2 AlTMP and Ga(CH SiMe 3 ) , structurally mapping their TMT reactions probing relative stabilities metalated fluoroaromatic intermediates by NMR studies. Results show...

Abstract Indoles are privileged heterocycles found in many biologically active pharmaceuticals and natural products. However, the selective functionalization of benzenoid moiety indoles preference to more reactive pyrrolic unit is a significant challenge. Herein we report that N‐acyl directing groups enable C7‐selective C−H borylation using just BBr 3 . This transformation shows some functional‐group tolerance notably proceeds with C6 substituted indoles. The group can be readily removed...

Abstract This study establishes a new trans‐metal‐trapping (TMT) procedure based on mixture of LiTMP (the base) and tris(trimethylsilylmethyl)gallium [Ga(CH 2 SiMe 3 ) , GaR ] trap) that, operating in tandem manner, is effective for the regioselective deprotonation sensitive diazines hydrocarbon solution, as illustrated through reactions pyrazine, pyridazine, pyrimidine, well N‐S heterocycle benzothiazole. The metallo‐activated complexes all these compounds were isolated structurally defined.

In the synthesis of Ni(II) salicylaldehyde 4-phenyl and 4-methyl-thiosemicarbazonato complexes conventional, electrochemical mechanochemical routes were applied compared. Polynuclear tetrahedral [Ni(sal 4-Metsc)]n (1) mononuclear square planar 4-Phtsc)(H2sal 4-Phtsc)]·CH3OH (2) obtained by conventional method. The proved to be a simple efficient route for brownish-red single crystals polycrystalline green octahedral [Ni(Hsal 4-Metsc)2]·(3) complexes, while liquid-assisted was fast...