Transi’onMetalFree Oxyaryla’on of Alkenes with Aryl Diazonium Salts and TEMPONa Joshua Sacher Wipf Group Current Literature October 6, 2012 Marcel Hartmann, Yi Li, and Armido Studer J. Am. Chem. Soc. ASAP DOI: 10.1021/ja307638u R N 2 BF 4 R O N TEMPO-Na + Josh Sacher @ Wipf Group Page 1 of 14 10/6/2012
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Transi'on-‐Metal-‐Free Oxyaryla'on of Alkenes with Aryl Diazonium Salts and TEMPONa
Joshua Sacher Wipf Group Current Literature
October 6, 2012
Marcel Hartmann, Yi Li, and Armido Studer J. Am. Chem. Soc. ASAP DOI: 10.1021/ja307638u
RN2BF4
R
O NTEMPO-Na
+
Josh Sacher @ Wipf Group Page 1 of 14 10/6/2012
PharmaceuMcals and Natural Products
OHMe2N
MeO
Effexor
OMe
OMeOMe
OHMeO OH
Combrestatin
O
O
NMe2
Darvon
N
OHHO
O
OH
O
Rohitukine
OHOH
NH
OO O
OH
HO
Coumabiocin F
de Souza, N. J. In Human Medicinal Agents from Plants. ACS, 1993, 331 Cheenpracha, S.; Vidor, N. B.; Yoshida, W. Y.; Davies, J.; Chang, L. C. J. Nat. Prod. 2010, 73, 880.
Josh Sacher @ Wipf Group Page 2 of 14 10/6/2012
Alkene ArylaMon • Heck ReacMon
• TM Catalyzed CarboetherificaMon/aminaMon
XR
RM, ligand, base+
R
[M]
R
Z
X = halogen, OTf
Z = OR, NR2
ZH ZAr
Ar XM, ligand, base
Wolfe, J. P. Synle?, 2008, 2913. Schultz, D. M.; Wolfe, J. P. Synthesis, 2012, 44, 351
Ball, L. T.; Green, M.; Lloyd-‐Jones, G. C.; Russell, C. A. Org. Le?. 2010, 12, 4724 Melhado, A. D.; Brezovich, W. E., Jr.; Lackner, A. D.; Toste, F. D. J. Am. Chem. Soc. 2010, 132, 8885
• New method for oxyarylaMon of alkenes • PotenMally useful alternaMve to TM cat reacMons • Mild condiMons, fast reacMons • Good funcMonal group compaMbility • Unaffected by sterics/electronics • Easy to do further transformaMons
• Drawbacks • Low yields for aliphaMc alkenes • Excess alkene needed • TEMPO-‐Na freshly prepared • More substrates? SelecMvity with dienes?
Josh Sacher @ Wipf Group Page 12 of 14 10/6/2012
Josh Sacher @ Wipf Group Page 13 of 14 10/6/2012
Au-‐catalyzed Mechanism
Melhado, A. D.; Brezovich, W. E., Jr.; Lackner, A. D.; Toste, F. D. J. Am. Chem. Soc. 2010, 132, 8885 Tkatchouk, E.; Mankad, N. P.; Benitez, D.; Goddard, W. A., III; Toste, F. D. J. Am. Chem. Soc. 2011, 133, 14293