Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Jul;26(11):1520-1524.
doi: 10.1055/s-0034-1381006. Epub 2015 Jun 15.

Rhodium(III)-Catalyzed C-H Activation: An Oxidative Intramolecular Heck-Type Reaction Directed by a Carboxylic Acid

Tyler A Davis  1 , Chuanqi Wang  1 , Tomislav Rovis  1
Affiliations

Rhodium(III)-Catalyzed C-H Activation: An Oxidative Intramolecular Heck-Type Reaction Directed by a Carboxylic Acid

Tyler A Davis et al. Synlett. 2015 Jul.

Abstract

Carboxylic acids effectively direct C-H activation for Rhodium(III)-catalyzed intramolecular Heck-type reactions. A catalytic amount of Cu(OAc)2 is used as the external oxidant with oxygen likely acting as the terminal oxidant. Additionally, a novel electron-deficient RhIII catalyst was found to be more effective that [RhCp*Cl2]2 with some substrates. A wide variety of complex dihydrobenzofurans, dihydrobenzopyrans, and other bicycles that can be easily further functionalized are now accessible through relatively mild reaction conditions.

Keywords: C-H activation; Heck reaction; Rhodium (III) catalysis; cyclization; dihydrobenzofurans.

PubMed Disclaimer

Figures

Scheme 1
Scheme 1
Previous and Current Work
Scheme 2
Scheme 2
Scope of Intramolecular Heck-type Reactions. aReactions conducted on 0.1 mmol scale in 1,2-dichloroethane:water (250 μL each, 0.2 M) in sealed vials purged under an O2 atmosphere at 60 °C. bIsolated with 20% impurity.
Scheme 3
Scheme 3
aSee Scheme 2 for reaction conditions. b10:1 E/Z. c7:1 E/Z. d5 mol% [RhCp*Cl2]2, 80 mol% Cu(OAc)2 used. Reaction time = 35h. Isolated as a 3:1 product:substrate mixture (yield based on recovered starting material), product was 5:1 E/Z.
See this image and copyright information in PMC

References

    1. For recent reviews on RhIII C-H activation, see: Satoh T, Miura M. Chem Eur J. 2010;16:11212–11222.Song G, Wang F, Li X. Chem Soc Rev. 2012;41:3651–3678.

    1. Examples of RhIII-catalyzed amidoarylations with alkynes: Guimond N, Gouliaras C, Fagnou K. J Am Chem Soc. 2010;132:6908–6909.Hyster TK, Rovis T. J Am Chem Soc. 2010;132:10565–10569.Amidoarylations with alkenes: Rakshit S, Grohmann C, Besset T, Glorius F. J Am Chem Soc. 2011;133:2350–2353.Hyster TK, Rovis T. Synlett. 2013:1842–1844.Olefinations: Patureau FW, Besset T, Glorius F. Angew Chem Int Ed. 2011;50:1064–1067.(f) see ref. . Halogenations: Schröder N, Wencel-Delord J, Glorius F. J Am Chem Soc. 2012;134:8298–8301.Allylations: Wang H, Schröder N, Glorius F. Angew Chem Int Ed. 2013;52:5386–5389.

    1. For examples of enantioselective RhIII-catalyzed reactions, see: Hyster TK, Knörr L, Ward TR, Rovis T. Science. 2012;338:500–503.Ye B, Cramer N. Science. 2012;338:504–506.Ye B, Donets PA, Cramer N. Angew Chem Int Ed. 2014;53:507–511.

    1. For a recent review on carboxylate-directed C-H activation, see: Shi G, Zhang Y. Adv Synth Catal. 2014;356:1419–1442.

    1. Satoh and Miura have described a RhIII-catalyzed carboxylic acid directed olefination and subsequent conjugate addition of the carboxylate to form lactones from benzoic acids and acrylates: Ueura K, Satoh T, Miura M. Org Lett. 2007;9:1407–1409.