Metal-free photoinduced C(sp3)–H borylation of alkanes
作者:Chao Shu、Adam Noble、Varinder K. Aggarwal
DOI:10.1038/s41586-020-2831-6
日期:2020.10.29
precious-metal catalysts for C-H bond cleavage and, as a result, display high selectivity for borylation of aromatic C(sp2)-H bonds over aliphatic C(sp3)-H bonds4. Here we report a mechanistically distinct, metal-free borylation using hydrogen atom transfer catalysis5, in which homolytic cleavage of C(sp3)-H bonds produces alkylradicals that are borylated by direct reaction with a diboron reagent. The reaction
Copper‐Catalyzed Amidation of Primary and Secondary Alkyl Boronic Esters
作者:Luis M. Mori‐Quiroz、Kirk W. Shimkin、Sina Rezazadeh、Ryan A. Kozlowski、Donald A. Watson
DOI:10.1002/chem.201603677
日期:2016.10.24
The oxidative copper‐catalyzed cross‐coupling of functionalized alkyl boronic esters with primary amides is reported. Through the identification of appropriate diketimine ligands, conditions for efficient coupling of both primary and secondaryalkyl boronic esters with diverse primary amides, including acetamide, have been developed.
Enantioselective installation of adjacent tertiary benzylic stereocentres using lithiation–borylation–protodeboronation methodology. Application to the synthesis of bifluranol and fluorohexestrol
作者:Stefan Roesner、Daniel J. Blair、Varinder K. Aggarwal
DOI:10.1039/c4sc03901g
日期:——
Highly hindered benzylic carbamates have been reacted with hindered boronic esters to give tertiary boronic esters with very high diastereo- and enantiocontrol and the methodology has been applied to otherwise difficult-to-access molecules.
Controllable Regiodivergent Alkynylation of 1,3‐Bis(Boronic) Esters Activated by Distinct Organometallic Reagents
作者:Ang Chen、Yang Qiao、De‐Wei Gao
DOI:10.1002/anie.202312605
日期:2023.11.27
An efficient method for controllable regiodivergent alkynylation of 1,3-bis(boronic) esters using distinct organometallicreagents has been developed. Mechanistic studies revealed that unique chelation patterns are essential in determining selectivity. This approach overcomes the drawbacks associated with coupling reactions through radical mechanisms, which commonly yield the classical products reacting
Photoredox-enabled 1,2-dialkylation of α-substituted acrylates <i>via</i> Ireland–Claisen rearrangement
作者:Roman Kleinmans、Leon E. Will、J. Luca Schwarz、Frank Glorius
DOI:10.1039/d0sc06385a
日期:——
for the synthesis of valuable tertiary carboxylic acids by merging Giese-type radical addition with an Ireland–Claisenrearrangement. Key to success is the utilization of the reductive radical-polar crossover concept under photocatalytic reaction conditions to force the [3,3]-sigmatropic rearrangement after alkyl radical addition to allyl acrylates. Using readily available alkyl boronic acids as radical