Correction: An un-forgotten classic: the nitro-Mannich reaction between nitrones and silyl nitronates catalysed by B(CF).

[This corrects the article DOI: 10.1039/D3SC05672D.].

Diverse Reactivity of Amidinate-Supported Boron Centers with the Hypersilyl Anion and Access to a Monomeric Secondary Boron Hydride.

Diverse reactivity of the bulky tris(trimethylsilyl)silyl substituent [Si(SiMe)], also known as the hypersilyl group, was observed for amidinate-supported dichloro- and phenylchloroborane complexes. Treatment of the dichloroborane with potassium tris(trimethylsilyl)silyl led to the activation of the backbone β-carbon center and formation of saturated four-membered heterocyclic chloroboranes R'{Si(SiMe)}C(NR)BCl [R' = Ph, R = Cy (); R' = Ph, R = Pr (); R' = Bu, R = Cy ()], whereas the four-membered amidinate hypersilyl-substituted phenyl borane {PhC(NCy)B(Ph)[Si(SiMe)]} was observed for the case of an amidinate-supported phenylchloroborane. The highly deshielded B NMR spectroscopic resonance and the distinct difference in the Si NMR spectrum confirmed the presence of a σ-donating hypersilyl effect on compounds , , and .

An un-forgotten classic: the nitro-Mannich reaction between nitrones and silyl nitronates catalysed by B(CF).

Herein we report the B(CF)-catalysed nitro-Mannich reaction between nitrones and silyl nitronates, affording silyl-protected α-nitro hydroxylamines with yields up to 99% and diastereoselectivities up to 99 : 1. Crucially, the obtained products can be converted into 1,2-diamines under simple reductive conditions. This work provides a new orthogonal method to the existing routes for the instalment of a nitro moiety under Lewis acid catalysed conditions, and expands the state-of-the-art substrate scope with respect to the silyl nitronates.

Advances in CO activation by frustrated Lewis pairs: from stoichiometric to catalytic reactions.

The rise of CO concentrations in the environment due to anthropogenic activities results in global warming and threatens the future of humanity and biodiversity. To address excessive CO emissions and its effects on climate change, efforts towards CO capture and conversion into value adduct products such as methane, methanol, acetic acid, and carbonates have grown. Frustrated Lewis pairs (FLPs) can activate small molecules, including CO and convert it into value added products.

Reactivity of a series of triaryl borates, B(OAr), in hydroboration catalysis.

In this paper, we compare the reactivity of a series of triaryl borates B(OAr) as catalysts for the hydroboration of alkenes and alkynes. It was observed that commercially available B(OPh) performed the poorest, whereas catalysts with -F atoms appeared to perform much better.

Synthesis and lewis acidity of fluorinated triaryl borates.

A series of fluorinated triaryl borates B(OAr) (Ar = 2-FCH, 3-FCH, 4-FCH, 2,4-FCH, 3,5-FCH, 2,3,4-FCH, 2,4,6-FCH, 3,4,5-FCH) have been prepared and isolated from the reactions of the mono-, di-, or tri-fluorophenol with BCl. The Lewis acidity of these borates has been determined by NMR spectroscopic and theoretical methods and compared to their well-established borane counterpart.

B(CF)-Catalyzed Diastereoselective and Divergent Reactions of Vinyldiazo Esters with Nitrones: Synthesis of Highly Functionalized Diazo Compounds.

Herein we report a mild, transition-metal-free, highly diastereoselective Lewis acid catalyzed methodology toward the synthesis of isoxazolidine-based diazo compounds from the reaction between vinyldiazo esters and nitrones. Interestingly, the isoxazolidine products were identified to have contrasting diastereoselectivity to previously reported metal-catalyzed reactions. Furthermore, the same catalyst can be used with enol diazo esters, prompting the formation of Mukaiyama-Mannich products.

An International Study Evaluating Elemental Analysis.

Based on statistical analysis of CHN combustion results of 18 international service providers, it is determined that the ±0.4% deviation most commonly required by chemistry journals is not justified.

Lewis Acid Assisted Brønsted Acid Catalysed Decarbonylation of Isocyanates: A Combined DFT and Experimental Study.

An efficient and mild reaction protocol for the decarbonylation of isocyanates has been developed using catalytic amounts of Lewis acidic boranes. The electronic nature (electron withdrawing, electron neutral, and electron donating) and the position of the substituents (ortho/meta/para) bound to isocyanate controls the chain length and composition of the products formed in the reaction. Detailed DFT studies were undertaken to account for the formation of the mono/di-carboxamidation products and benzoxazolone compounds.