C–H functionalisation of aldehydes using light generated, non-stabilised diazo compounds in flow
作者:Paul Dingwall、Andreas Greb、Lorène N. S. Crespin、Ricardo Labes、Biagia Musio、Jian-Siang Poh、Patrick Pasau、David C. Blakemore、Steven V. Ley
DOI:10.1039/c8cc06202a
日期:——
Here we explore further the use of oxadiazolines, non-stabilised diazo precursors which are bench stable, in direct, non-catalytic, aldehyde C–H functionalisation reactions under UV photolysis in flow and free from additives.
Photochemical Homologation for the Preparation of Aliphatic Aldehydes in Flow
作者:Yiding Chen、Marco Leonardi、Paul Dingwall、Ricardo Labes、Patrick Pasau、David C. Blakemore、Steven V. Ley
DOI:10.1021/acs.joc.8b02721
日期:2018.12.21
formaldehyde was used as a formylating reagent in a homologation reaction with nonstabilized diazo compounds, enabled by UV photolysis of bench-stable oxadiazolines in a flow photoreactor. Various aliphatic aldehydes were synthesized along with the corresponding derivatized alcohols and benzimidazoles. No transition-metal catalyst or additive was required to affect the reaction, which proceeded at room temperature
Three-Component Assembly of Multiply Substituted Homoallylic Alcohols and Amines Using a Flow Chemistry Photoreactor
作者:Yiding Chen、David C. Blakemore、Patrick Pasau、Steven V. Ley
DOI:10.1021/acs.orglett.8b02907
日期:2018.10.19
Oxadiazolines are bench-stable diazo precursors, which are activated under UV radiation in the presence of vinylboronicacids and aldehydes to enable a one-step three-component assembly of densely functionalized homoallylic alcohols. Substitution on all positions of the homoallylic alcohol product were achieved with high functional group tolerance. No catalyst or other additive was required to effect
Pseudosymmetry and phase transition in dimethyl 2,3-bis(tricyclo[3.3.1.1<sup>3,7</sup>]dec-2-ylidene)butanedioate
作者:Jan W. Bats、Marc A. Grundl、A. Stephen K. Hashmi
DOI:10.1107/s0108270101003845
日期:2001.5.15
The crystal structure of the title compound, C26H34O4, shows a reversible phase transition at about 178 K. The structure of the high-temperature phase contains two independent molecules related by pseudosymmetry elements. Cooling through the phase-transition temperature results in a doubling of the c axis. The low-temperature structure contains four independent molecules related by pseudosymmetry elements. The phase transition results in a rearrangement of some weak intermolecular C-H . . . O interactions. The number of very weak C-H . . . O interactions, with H . . . O distances between 2.8 and 2.9 Angstrom, is increased in the low-temperature structure.
A Versatile Route to Unstable Diazo Compounds via Oxadiazolines and their Use in Aryl-Alkyl Cross-Coupling Reactions
作者:Andreas Greb、Jian-Siang Poh、Stephanie Greed、Claudio Battilocchio、Patrick Pasau、David C. Blakemore、Steven V. Ley
DOI:10.1002/anie.201710445
日期:2017.12.22
Coupling of readily available boronicacids and diazo compounds has emerged recently as a powerful metal-free carbon-carbon bond forming method. However, the difficulty in forming the unstable diazo compound partner in a mild fashion has hitherto limited their general use and the scope of the transformation. Here, we report the application of oxadiazolines as precursors for the generation of an unstable