Asymmetric Retro-Claisen Reaction by Synergistic Chiral Primary Amine/Palladium Catalysis
作者:Yanfang Han、Long Zhang、Sanzhong Luo
DOI:10.1021/acs.orglett.9b02491
日期:2019.9.20
We described herein a chiral primaryamine/palladium catalyzed asymmetric retro-Claisen reaction of β-diketones with salicylic carbonates. A series of chiral α-alkylated ketones and macrolides were obtained with good yields and excellent enantioselectivities upon a sequence of decarboxylative benzylation, retro-Claisen cleavage, and enamine protonation. This strategy features broad substrate scope
Neighboring group participation in Lewis acid-promoted [3 + 4] and [3 + 5] annulations. The synthesis of oxabicyclo[3.n.1]alkan-3-ones
作者:Gary A. Molander、Kimberly O. Cameron
DOI:10.1021/ja00056a002
日期:1993.2
2-(alkoxycarbon)-m-oxabicyclo[3.n.1]alkan-3-ones can be constructed by this process in which two new carbon-carbon bonds are generated. Unusually high regioncontrol is observed, and good to excellent stereochemicalcontrol can be achieved at virtually every position on the new carbocycles. Intramolecular neighboringgroupparticipation is proposed to explain the unusually high selectivities attained in the annulation
Broad spectrum beta-lactamase inhibitors. Certain inhibitors also exhibit potent antibiotic activity in addition to beta-lactamase inhibition. Compounds of the invention are designed such that on cleavage of the beta-lactam ring reactive moieties are generated which can inactivate beta-lactamase. Also provided are methods of making beta-lactamase inhibitors and beta-lactam antibiotics exhibiting such inhibition. Additionally provided are pharmaceutical compositions for treatment or prevention of bacterial infections and methods of treatment of such infections.