1. Palladium-catalyzed decarboxylative allylation and benzylation of N-alloc and N-Cbz indoles
Thomas D Montgomery, Ye Zhu, Natsuko Kagawa, Viresh H Rawal Org Lett. 2013 Mar 1;15(5):1140-3. doi: 10.1021/ol400334u. Epub 2013 Feb 21.
A set of general methods for the palladium-catalyzed decarboxylative C3-allylation and C3-benzylation of indoles, starting from the corresponding N-alloc and N-Cbz indoles, respectively, is reported. This chemistry provides ready access to a wide range of functionalized indolenines in good to excellent yields. A tandem process, wherein the palladium catalyzed allylation chemistry is coupled with a Mizoroki-Heck reaction, offers a simple route to cinnamylated products.
2. Regio- and Stereospecific C- and O-Allylation of Phenols via π-Allyl Pd Complexes Derived from Allylic Ester Carbonates
Christopher A Discolo, Alexander G Graves, Donald R Deardorff J Org Chem. 2017 Jan 20;82(2):1034-1045. doi: 10.1021/acs.joc.6b02608. Epub 2016 Dec 29.
Two complementary strategies have been developed for the C- and O-allylation of phenols via a common π-allyl Pd complex. While O-allylation of phenols by this method is a well-recognized reaction of general utility, the associated para-selective C-allylation reaction is still in its infancy. Cationic π-allyl Pd intermediates, derived from allylic ester carbonates and palladium(0) catalyst, were found to undergo the Friedel-Crafts-type para-selective C-allylations with nine different phenols. Both C- and O-allylated products were obtained in good to excellent yields following a metal-catalyzed regio- and stereospecific substitutive 1,3-transposition. Conditions were also identified that control access to either allylated product. Finally, a study of the equilibrium established between the two allylation products revealed that the O-allylated compound was the kinetic product and the C-allylated compound the thermodynamic product.
3. Pd-catalyzed C3-selective allylation of indoles with allyl alcohols promoted by triethylborane
Masanari Kimura, Makoto Futamata, Ryutaro Mukai, Yoshinao Tamaru J Am Chem Soc. 2005 Apr 6;127(13):4592-3. doi: 10.1021/ja0501161.
Under palladium catalysis, Et3B nicely promotes allyl alcohols to undergo C3-selective allylation of indoles and tryptophan; the yields range 75-95%.
