Synthesis of 6-carbon termini-differentiated stereotriads via symchiral 2-trifloxy-1,3-cyclohexadiene monoepoxide
摘要:
Jacobsen epoxidation of 2-trifloxy-1,3-cyclohexadiene provides a valuable asymmetric monoepoxide product that can be readily manipulated to efficiently provide highly-functionalized symchiral cyclic and acyclic synthons. (C) 1999 Elsevier Science Ltd. All rights reserved.
The Diels-Alder cycloadditions of the alpha-acetoxynitroso dienophile in water are reported. The rapid and high yielding synthesis of structurally diverse 3,6-dihydro-1,2-oxazines complements the straightforward elaboration of aminoalcohols obtained from the alpha-acetoxynitroso derivative in anhydrous medium. A rationale for this solvent-dependent product distribution is proposed.
Synthesis of Polycyclic Nitrogen Heterocycles via Cascade Pd-Catalyzed Alkene Carboamination/Diels–Alder Reactions
作者:Derick R. White、John P. Wolfe
DOI:10.1021/acs.orglett.5b00896
日期:2015.5.15
Cascade Pd-catalyzed alkenecarboamination/Diels–Alder reactions between bromodienes and amines bearing two pendant alkenes are described. These transformations generate 4 bonds, 3 rings, and 3–5 stereocenters to afford polycyclic nitrogen heterocycles with high diastereoselectivity.
An electrochemical synthesis of functionalized (aza)indolinesthrough dehydrogenative [3+2] annulation of arylamines with tethered alkenes has been developed. Previous reported syntheses through similar inter‐ and intramolecular annulation reactions required noble‐metal catalysts and are mostly limited to terminal alkenes or 1,3‐dienes. The electrosynthesis employs the easily available and inexpensive
Palladium-Catalyzed Cross-Coupling Reaction of Bis(pinacolato)diboron with 1-Alkenyl Halides or Triflates: Convenient Synthesis of Unsymmetrical 1,3-Dienes via the Borylation-Coupling Sequence
1-alkenylboronic acid pinacol esters via a palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron (pin(2)B(2), pin = Me(4)C(2)O(2)) with 1-alkenyl halides or triflates was carried out in toluene at 50 degrees C in the presence of KOPh (1.5 equiv) and PdCl(2)(PPh(3))(2)-2Ph(3)P (3 mol %). The borylation of acyclic and cyclic 1-alkenyl bromides and triflates was achieved in high yields with complete
Asymmetric 1,4-Dihydroxylation of 1,3-Dienes by Catalytic Enantioselective Diboration
作者:Heather E. Burks、Laura T. Kliman、James P. Morken
DOI:10.1021/ja809610h
日期:2009.7.8
studies reported in this communication suggest that both cyclic and acyclic substrates will participate in this reaction; however, dienes which are unable to adopt the S-cis conformation are unreactive. For most substrates, 1,4-addition is the predominant pathway. In addition to oxidation to the derived 2-buten-1,4-diol, stereoselective carbonyl allylation with the intermediate bis(boronate) ester is