1581275-99-1Relevant articles and documents
Diastereoselective Synthesis of Axially Chiral Xylose-Derived 1,3-Disubstituted Alkoxyallenes: Scope, Structure, and Mechanism
Fortunato, Moustapha,Gimbert, Yves,Rousset, Elodie,Lameiras, Pedro,Martinez, Agathe,Gatard, Sylvain,Plantier-Royon, Richard,Jaroschik, Florian
, p. 10681 - 10694 (2020)
The deprotonation of differently substituted propargyl xylosides with s-BuLi/TMEDA followed by protonation with t-butanol at -115 °C provided a range of new axially chiral 1,3-disubstituted alkoxyallenes in a diastereoselective way. Numerous reaction parameters such as solvent, temperature, or protonating agent were examined as well as protecting groups on the xyloside moiety and the influence of the substituents on the alkyne part. The configuration of the main diastereoisomer of 3-methyl-1-xyloside-allene was determined for the first time by single-crystal X-ray diffraction analysis and nOe NMR experiments. Furthermore, DFT calculations on the propargyl/allenyl lithium intermediates formed in the course of the deprotonation reaction provided new structural insights of these complexes. The subsequent protonation process with alcohols was investigated by theoretical surface exploration, revealing the importance of the approach of the alcohol toward the lithium compounds on the reaction outcome.
Kinetic Study of Carbophilic Lewis Acid Catalyzed Oxyboration and the Noninnocent Role of Sodium Chloride
Johnson, Joel S.,Chong, Eugene,Tu, Kim N.,Blum, Suzanne A.
, p. 655 - 662 (2016/04/20)
In the present study, the oxyboration reaction catalyzed by IPrAuTFA in the presence and absence of NaTFA has been examined with kinetic studies, mass spectrometry, and 1H NMR and 11B NMR spectroscopy. Data from monitoring the reacti
Alkoxyboration: Ring-closing addition of B-O σ bonds across alkynes
Hirner, Joshua J.,Faizi, Darius J.,Blum, Suzanne A.
, p. 4740 - 4745 (2014/04/17)
For nearly 70 years, the addition of boron-X σ bonds to carbon-carbon multiple bonds has been employed in the preparation of organoboron reagents. However, the significantly higher strength of boron-oxygen bonds has thus far precluded their activation for addition, preventing a direct route to access a potentially valuable class of oxygen-containing organoboron reagents for divergent synthesis. We herein report the realization of an alkoxyboration reaction, the addition of boron-oxygen σ bonds to alkynes. Functionalized O-heterocyclic boronic acid derivatives are produced using this transformation, which is mild and exhibits broad functional group compatibility. Our results demonstrate activation of this boron-O σ bond using a gold catalysis strategy that is fundamentally different from that used previously for other boron addition reactions.