Undeniable Confirmation of the syn-Addition Mechanism for Metal-Free Diboration by Using the Crystalline Sponge Method.
Ana B CuencaNicolas ZigonVincent DuplanManabu HoshinoMakoto FujitaElena FernándezPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2016)
The stereochemical outcome of the recently developed metal-free 1,2-diboration of aliphatic alkenes has, until now, only been elucidated by indirect means (e.g. derivatization). This is because classical conformational analysis of the resulting 1,2-diboranes is not viable; in the (1)H NMR spectrum the relevant (1)H resonances are broadened by (11)B, and the occurrence of the products as oily compounds precludes X-ray crystallographic analysis. Herein, the crystalline sponge method is used to display the crystal structures of the diboronic esters formed from internal E and Z olefins, evidencing the stereospecific syn addition mechanism of the reaction, which is fully consistent with the prediction from DFT calculations.
Keyphrases
- density functional theory
- molecular dynamics
- molecular dynamics simulations
- high resolution
- room temperature
- risk assessment
- magnetic resonance
- ms ms
- liquid chromatography tandem mass spectrometry
- solid state
- liquid chromatography
- mass spectrometry
- dual energy
- magnetic resonance imaging
- computed tomography
- gas chromatography
- crystal structure
- high resolution mass spectrometry