1428538-13-9Relevant academic research and scientific papers
Desymmetrization of C2-Symmetric Bis(Boronic Esters) by Zweifel Olefinations
Linne, Yannick,Sch?nwald, Axel,Wei?bach, Sebastian,Kalesse, Markus
supporting information, p. 7998 - 8002 (2020/06/09)
anti-Configured 1,3-dimethyl deoxypropionate motifs are important sub structures in natural products. Herein, we describe a bidirectional approach for the rapid construction of natural products featuring such motifs by using C2-symmetrical 1,3-bis(boronic esters). As for its application in convergent syntheses it was important to establish a selective mono-Zweifel olefination we describe the scope and limitations by using different 1,3-bis(boronic esters) and nucleophiles. This protocol takes advantage of the combination of the Hoppe–Matteson–Zweifel chemistry, which was elegantly put into practice by Aggarwal et al. In order to show its applicability the total syntheses of two natural products, serricornin and (+)-invictolide, were performed.
Regio- and Stereoselective Homologation of 1,2-Bis(Boronic Esters): Stereocontrolled Synthesis of 1,3-Diols and Sch 725674
Fawcett, Alexander,Nitsch, Dominik,Ali, Muhammad,Bateman, Joseph M.,Myers, Eddie L.,Aggarwal, Varinder K.
supporting information, p. 14663 - 14667 (2016/11/23)
1,2-Bis(boronic esters), derived from the enantioselective diboration of terminal alkenes, can be selectively homologated at the primary boronic ester by using enantioenriched primary/secondary lithiated carbamates or benzoates to give 1,3-bis(boronic esters), which can be subsequently oxidized to the corresponding secondary-secondary and secondary-tertiary 1,3-diols with full stereocontrol. The transformation was applied to a concise total synthesis of the 14-membered macrolactone, Sch 725674. The nine-step synthetic route also features a novel desymmetrizing enantioselective diboration of a divinyl carbinol derivative and high-yielding late-stage cross-metathesis and Yamaguchi macrolactonization reactions.
Highly diastereo- and enantioselective allylboration of aldehydes using α-substituted allyl/crotyl pinacol boronic esters via in situ generated borinic esters
Chen, Jack L.-Y.,Scott, Helen K.,Hesse, Matthew J.,Willis, Christine L.,Aggarwal, Varinder K.
supporting information, p. 5316 - 5319 (2013/05/21)
Readily available, α-substituted allyl/crotyl pinacol boronic esters often give low E/Z selectivity (with Z favored) in reactions with aldehydes. We found that addition of nBuLi to the pinacol boronic ester followed by trapping of the alkoxide with TFAA leads to an intermediate allyl borinic ester which undergoes allylboration with very high E selectivity. The substrate scope includes primary to tertiary alkyl α-substituents, crotyl substrates, and the previously unreported β-methallyl pinacol boronic esters. The latter give very high Z selectivity under standard conditions which is completely reversed to high E selectivity under the new conditions. Monitoring the reaction by 11B NMR confirmed that the reaction proceeds through a borinic ester intermediate.
