Synthesis of Acylboron Compounds

Wu, Dino; Taguchi, Jumpei; Tanriver, Matthias; Bode, Jeffrey W.

doi:10.1002/anie.202005050

Cited by 30 publications

(9 citation statements)

References 113 publications

(69 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Next, we envisioned that replacing PhMe 2 Si-Bpin with B 2 pin 2 would enable the synthesis of acylboron compounds . However, a main challenge here is the notorious instability of tricoordinate acylboron compounds .…”

Section: Carbonylative Silylation and Borylation Of Alkyl Halidesmentioning

confidence: 99%

Copper-Catalyzed Carbonylative Coupling of Alkyl Halides

Cheng

Mankad

2021

Acc. Chem. Res.

View full text Add to dashboard Cite

Conspectus Transition metal-catalyzed carbonylation reactions represent a direct and atom-economical approach to introduce oxygen functionality into organic compounds, with CO acting as an inexpensive and readily available C1 feedstock. Despite the long history of carbonylation catalysis, including many processes that have been industrialized at bulk scale, there remain several challenges to tackle. For example, noble metals such as Pd, Rh, and Ir are typically used as catalysts for carbonylation reactions, rather than earth-abundant alternatives. Additionally, while carbonylation of C(sp2)-hybridized substrates (e.g., aryl halides) is well-known, carbonylation of unactivated alkyl electrophiles, especially where β-hydride elimination can compete with desired CO migratory insertion at the catalyst site, remains challenging for many systems. Recently, base metal catalysis based on Mn, Co, and other metals has enabled advances in carbonylative coupling of alkyl electrophiles, though the nucleophiles are often limited to alcohols or amines to generate esters or amides as products. Thus, we have targeted base metal-catalyzed carbonylative C–C and C–E (E = N, H, Si, B) coupling reactions as a method for approaching diverse carbonyl compounds of synthetic importance. Initially, we designed a heterobimetallic catalyst platform for carbonylative C–C coupling of alkyl halides with arylboronic esters (i.e., carbonylative Suzuki–Miyaura coupling) to generate aryl alkyl ketones. Subsequently, we developed multicomponent carbonylation reactions of alkyl halides using NHC-Cu catalysts (NHC = N-heterocyclic carbene). These reactions operate by radical mechanisms, converting alkyl halides into either acyl radical or acyl halide intermediates that undergo subsequent C–C or C–E coupling at the Cu site. This mechanistic paradigm is relatively novel in the metal-catalyzed carbonylation area, allowing us to discover a previously unexplored chemical space in carbonylative coupling catalysis. We have successfully developed the following reactions: (a) hydrocarbonylative coupling of alkynes with alkyl halides; (b) borocarbonylative coupling of alkynes with alkyl halides; (c) reductive aminocarbonylation of alkyl halides with nitroarenes; (d) reductive carbonylation of alkyl halides; (e) carbonylative silylation of alkyl halides; (f) carbonylative borylation of alkyl halides. These reactions provide a broad range of valuable products including ketones, allylic alcohols, β-borylenones, amides, alcohols, acylsilanes, and acylborons in an efficient manner. Notably, the preparation of some of these products has previously required multistep syntheses, harsh conditions, or specialized reagents. By contrast, the multicomponent coupling platform that we have developed requires only readily available building blocks and rapidly increases molecular complexity in a single synthetic manipulation.

show abstract

Section: Carbonylative Silylation and Borylation Of Alkyl Halidesmentioning

confidence: 99%

Copper-Catalyzed Carbonylative Coupling of Alkyl Halides

Cheng

Mankad

2021

Acc. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Another useful strategy is to start with borylated building blocks. By heterocyclization, the heteroaromatic ring is formed, and the boryl moiety is retained in the product . This strategy offers a more flexible and diverse synthesis of heteroaromatic borons, but the availability of borylated building blocks is often limiting (Figure a).…”

mentioning

confidence: 99%

Radical Borylative Cyclization of Isocyanoarenes with N-Heterocyclic Carbene Borane: Synthesis of Borylated Aza-arenes

Liu

et al. 2021

Org. Lett.

View full text Add to dashboard Cite

Borylated aza-arenes are of great importance in the area of organic synthesis. A radical borylative cyclization of isocyanoarenes with N-heterocyclic carbene borane (NHC-BH3) under metal-free conditions was developed. The reaction allows the efficient assembly of several types of borylated aza-arenes (phenanthridines, benzothiazoles, etc.), which are difficult to access using alternative methods. Mild reaction conditions, a good functional-group tolerance, and generally good efficiencies were observed. The utility of these products is demonstrated, and the mechanism is discussed.

show abstract

“…The CO ligands in the BH borenium carbonyls 10 a,b are apparently inert to intramolecular reduction by the adjacent B-H functionality. However, the carbonyl moiety at the positively charged borenium core is activated for external nucleophilic attack by the neutral carbon nucleophile IMes The reaction of the borenium carbonyl salt 10 a with the IMesCH 2 reagent gave the substituted acetyl boron [16] cation system 12, formed by nucleophilic endiamine attack at the BÀ C O carbon atom, in 94 % yield (Scheme 4). The X-ray crystal structure of compound 12 shows the presence of the newly formed IMes-substituted acetyl group attached at boron.…”

Section: Communicationsmentioning

confidence: 99%

The [(NHC)B(H)C₆F₅]⁺ Cations and Their [B](H)−CO Borane Carbonyls

Chen

Daniliuc

et al. 2020

Angew Chem Int Ed

View full text Add to dashboard Cite

Hydride abstraction from the heterocyclic carbene borane adducts (NHC)BH 2 C 6 F 5 (NHC: IMes or IMe 4) gave the BÀH containing [(NHC)B(H)C 6 F 5 ] + borenium cations. They added carbon monoxide to give the respective [(NHC)B-(H)(C 6 F 5)CO] + boron carbonyl cations. Carbon nucleophiles add to the boron carbonyl to give [B](H) acyls. Hydride reduced the [B]CO cation to hydroxymethylborane derivatives.

show abstract

Synthesis of Acylboron Compounds

Cited by 30 publications

References 113 publications

Copper-Catalyzed Carbonylative Coupling of Alkyl Halides

Copper-Catalyzed Carbonylative Coupling of Alkyl Halides

Radical Borylative Cyclization of Isocyanoarenes with N-Heterocyclic Carbene Borane: Synthesis of Borylated Aza-arenes

The [(NHC)B(H)C₆F₅]⁺ Cations and Their [B](H)−CO Borane Carbonyls

Contact Info

Product

Resources

About

Synthesis of Acylboron Compounds

Cited by 30 publications

References 113 publications

Copper-Catalyzed Carbonylative Coupling of Alkyl Halides

Copper-Catalyzed Carbonylative Coupling of Alkyl Halides

Radical Borylative Cyclization of Isocyanoarenes with N-Heterocyclic Carbene Borane: Synthesis of Borylated Aza-arenes

The [(NHC)B(H)C6F5]+ Cations and Their [B](H)−CO Borane Carbonyls

Contact Info

Product

Resources

About

The [(NHC)B(H)C₆F₅]⁺ Cations and Their [B](H)−CO Borane Carbonyls