α‐Boryl Carbanions: The Influence of Geminal Heteroatoms in C−C Bond Formation DOI Creative Commons
Elena Fernández

The Chemical Record, Journal Year: 2024, Volume and Issue: 24(3)

Published: Feb. 2, 2024

Abstract The wide applications of alpha‐boryl carbanions in selective coupling with organohalides, imines/carbonyls and conjugated unsaturated substrates has become an interesting tool for organic synthesis. Strategically, the inclusion heteroatoms, such as Si, S, N, F, Cl, Br I alpha position opens a new venue towards multifunctionalities molecular design. Here, conceptual practical view on powerful carbanions, containing α‐silicoboron, α‐thioboron, α‐haloboron α‐aminoboron is given, well prespective their efficient application electrophilic trapping.

Language: Английский

Carbene-Catalyzed Enantioselective Sulfonylation of Enone Aryl Aldehydes: A New Mode of Breslow Intermediate Oxidation DOI
Rui Deng, Shuquan Wu, Chengli Mou

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(12), P. 5441 - 5449

Published: March 11, 2022

A carbene-catalyzed sulfonylation reaction between enone aryl aldehydes and sulfonyl chlorides is disclosed. The effectively installs sulfone moieties in a highly enantioselective manner to afford sulfone-containing bicyclic lactones. chloride behaves both as an oxidant nucleophilic substrate (via its reduced form) this N-heterocyclic carbene (NHC)-catalyzed process. NHC catalyst provides activation stereoselectivity control on very remote site of aldehyde substrates. Water plays important role modulating deactivation reactivation routes that involve reactions chloride. Experimental studies DFT calculations suggest unprecedented intermediate new oxidation mode the NHC-derived Breslow are involved asymmetric reaction.

Language: Английский

Citations

37

Defluorinative C–C Bond-Forming Reaction of Trifluoromethyl Alkenes with gem-(Diborylalkyl)lithiums DOI
Haeun Kim,

Yujin Jung,

Seung Hwan Cho

et al.

Organic Letters, Journal Year: 2022, Volume and Issue: 24(14), P. 2705 - 2710

Published: April 5, 2022

We report the transition-metal-free defluorinative C-C bond-forming reaction of trifluoromethyl alkenes with gem-(diborylalkyl)lithiums. This synthetic strategy provides access to a variety 4,4-difluoro homoallylic diboronate esters, which serve as versatile intermediates in efficient preparation valuable gem-difluoroalkene derivatives. Further modifications are conducted demonstrate utility obtained esters.

Language: Английский

Citations

30

Asymmetric Synthesis of Chiral 1,2‐Bis(Boronic) Esters Featuring Acyclic, Non‐Adjacent 1,3‐Stereocenters DOI

Xia‐Min Jiang,

Chong‐Lei Ji,

Jianfei Ge

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(5)

Published: Dec. 15, 2023

The construction of acyclic, non-adjacent 1,3-stereogenic centers, prevalent motifs in drugs and bioactive molecules, has been a long-standing synthetic challenge due to acyclic nucleophiles being distant from the chiral environment. In this study, we successfully synthesized highly valuable 1,2-bis(boronic) esters featuring nonadjacent 1,3-stereocenters. Notably, reaction selectively produces migratory coupling products rather than alternative deborylative allylation or direct byproducts. This approach introduces new activation mode for selective transformations gem-diborylmethane asymmetric catalysis. Additionally, found that other gem-diborylalkanes, previously challenging steric hindrance, also participated reaction. incorporation 1,2-bis(boryl)alkenes facilitated diversification alkenyl two boron moieties our target compounds, thereby enabling access broad array versatile molecules. DFT calculations were performed elucidate mechanism shed light on factors responsible observed excellent enantioselectivity diastereoselectivity. These determined arise ligand-substrate repulsions syn-addition transition state.

Language: Английский

Citations

22

A General Method to Access Sterically Encumbered Geminal Bis(boronates) via Formal Umpolung Transformation of Terminal Diboron Compounds DOI Open Access

Peng‐Fei Ning,

Yi Wei, Xinyi Chen

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(4)

Published: Dec. 8, 2023

Abstract General methods for the preparation of geminal bis(boronates) are great interest due to their widespread applications in organic synthesis. While terminal gem ‐diboron compounds readily accessible, construction sterically encumbered, internal analogues has remained a prominent challenge. Herein, we report formal umpolung strategy access these valuable building blocks. The available 1,1‐diborylalkanes were first converted into corresponding α‐halogenated derivatives, which then serve as electrophilic components, undergoing substitution with diverse array nucleophiles form series C−C, C−O, C−S, and C−N bonds. This protocol features good tolerance steric hindrance wide variety functional groups heterocycles. Notably, this can also be extended synthesis diaryl compounds, therefore providing general approach various types bis(boronates).

Language: Английский

Citations

21

α‐Boryl Carbanions: The Influence of Geminal Heteroatoms in C−C Bond Formation DOI Creative Commons
Elena Fernández

The Chemical Record, Journal Year: 2024, Volume and Issue: 24(3)

Published: Feb. 2, 2024

Abstract The wide applications of alpha‐boryl carbanions in selective coupling with organohalides, imines/carbonyls and conjugated unsaturated substrates has become an interesting tool for organic synthesis. Strategically, the inclusion heteroatoms, such as Si, S, N, F, Cl, Br I alpha position opens a new venue towards multifunctionalities molecular design. Here, conceptual practical view on powerful carbanions, containing α‐silicoboron, α‐thioboron, α‐haloboron α‐aminoboron is given, well prespective their efficient application electrophilic trapping.

Language: Английский

Citations

7