The boration reaction using B2pai2

Niu, Changhao; Li, Qi; Zhang, Chun

doi:10.1016/j.tet.2023.133381

“…Based on the previous reports on Cu‐catalyzed hydroboration and considering the control experiments above, [ 3 , 12 , 20 ] we proposed a plausible mechanism for the hydroboration where HBpin or B 2 pin 2 were involved ( Figure 1 ). The reaction is initiated by Cu‐H species B, which is generated through the reaction of Cu‐alkoxide A with pinacolborane.…”

Section: Resultsmentioning

confidence: 85%

Enantio‐ and Regioselective Cascade Hydroboration of Methylenecyclopropanes for Facile Access to Chiral 1,3‐ and 1,4‐Bis(boronates)

Zhou,

Meng,

Yang

et al. 2024

Advanced Science

0

View full text Add to dashboard Cite

Chiral 1, n‐bis(boronate) plays a crucial role in organic synthesis and medicinal chemistry. However, their catalytic and asymmetric synthesis has long posed a challenge in terms of operability and accessibility from readily available substrates. The recent discovery of the C═C bond formation through β‐C elimination of methylenecyclopropanes (MCP) has provided an exciting opportunity to enhance molecular complexity. In this study, the catalyzed asymmetric cascade hydroboration of MCP is developed. By employing different ligands, various homoallylic boronate intermediate are obtained through the hydroboration ring opening process. Subsequently, the cascade hydroboration with HBpin or B2pin2 resulted in the synthesis of enantioenriched chiral 1,3‐ and 1,4‐bis(boronates) in high yields, accompanied by excellent chemo‐ and enantioselectivities. The selective transformation of these two distinct C─B bonds also demonstrated their application potential in organic synthesis.

show abstract

Asymmetric Synthesis of Trisubstituted Vicinal Diols through Copper(I)‐Catalyzed Diastereoselective and Enantioselective Allylation of Ketones with Siloxypropadienes

Jiang,

Liu,

Pan

et al. 2024

Angewandte Chemie

0

View full text Add to dashboard Cite

Chiral trisubstituted vicinal diols are a type of important organic compounds, serving as both common structure units in bioactive natural products and chiral auxiliaries in asymmetric synthesis. Herein, by using siloxypropadienes as the precursors of allyl copper(I) species, a copper(I)‐catalyzed diastereoselective and enantioselective reductive allylation of ketones was achieved, providing both syn‐diols and anti‐diols in good to excellent enantioselectivity. DFT calculations show that cis‐γ‐siloxy‐allyl copper species are generated favorably with either 1‐TBSO‐propadiene or 1‐TIPSO‐propadiene. Moreover, the steric difference of TBS group and TIPS group distinguishes the face selectivity of acetophenone, leading to syn‐selectivity for 1‐TBSO‐propadiene and anti‐selectivity for 1‐TIPSO‐propadiene. Easy transformations of the products were performed, demonstrating the synthetic utility of the present method. Moreover, one chiral diol prepared in the above transformations was used as a suitable organocatalyst for the catalytic asymmetric reductive self‐coupling of aldimines generated in situ with B2(neo)2.

show abstract

Asymmetric Synthesis of Trisubstituted Vicinal Diols through Copper(I)‐Catalyzed Diastereoselective and Enantioselective Allylation of Ketones with Siloxypropadienes

Jiang,

Liu,

Pan

et al. 2024

Angew Chem Int Ed

1

0

View full text Add to dashboard Cite

Chiral trisubstituted vicinal diols are a type of important organic compounds, serving as both common structure units in bioactive natural products and chiral auxiliaries in asymmetric synthesis. Herein, by using siloxypropadienes as the precursors of allyl copper(I) species, a copper(I)‐catalyzed diastereoselective and enantioselective reductive allylation of ketones was achieved, providing both syn‐diols and anti‐diols in good to excellent enantioselectivity. DFT calculations show that cis‐γ‐siloxy‐allyl copper species are generated favorably with either 1‐TBSO‐propadiene or 1‐TIPSO‐propadiene. Moreover, the steric difference of TBS group and TIPS group distinguishes the face selectivity of acetophenone, leading to syn‐selectivity for 1‐TBSO‐propadiene and anti‐selectivity for 1‐TIPSO‐propadiene. Easy transformations of the products were performed, demonstrating the synthetic utility of the present method. Moreover, one chiral diol prepared in the above transformations was used as a suitable organocatalyst for the catalytic asymmetric reductive self‐coupling of aldimines generated in situ with B2(neo)2.

show abstract

The boration reaction using B2pai2

Cited by 6 publications

References 44 publications

Enantio‐ and Regioselective Cascade Hydroboration of Methylenecyclopropanes for Facile Access to Chiral 1,3‐ and 1,4‐Bis(boronates)

Enantio‐ and Regioselective Cascade Hydroboration of Methylenecyclopropanes for Facile Access to Chiral 1,3‐ and 1,4‐Bis(boronates)

Asymmetric Synthesis of Trisubstituted Vicinal Diols through Copper(I)‐Catalyzed Diastereoselective and Enantioselective Allylation of Ketones with Siloxypropadienes

Asymmetric Synthesis of Trisubstituted Vicinal Diols through Copper(I)‐Catalyzed Diastereoselective and Enantioselective Allylation of Ketones with Siloxypropadienes

Contact Info

Product

Resources

About