Friedel-Crafts Alkylation Of Indoles Research Articles

Friedel-Crafts Alkylation of Indoles with a Cu-DNA Catalyst

An impressive example of an enantioselective Friedel-Crafts reaction using water and a DNA-based catalyst is described. The catalyst is assembled in situ from Cu-dmbpy and salmon testes DNA, which is readily available and inexpensive. The reaction is compatible with a ­variety of substituents on the indole and olefin, ­although in some cases, using other DNA strands provided more optimal results. Results for both analytical and preparative scales are reported.

Enantioselective Friedel-Crafts Alkylation of Indoles with Alkylidene Malonates

Enantioselective Friedel-Crafts Alkylation of Indoles with Alkylidene Malonates

Friedel-Crafts Alkylation of Indole with Simple Enones

Friedel-Crafts Alkylation of Indole with Simple Enones

Catalytic Enantioselective Friedel−Crafts Alkylations of Indoles with α‘-Phosphoric Enones

The C2-symmetric bis(oxazoline) copper(II) complex proves to be an excellent catalyst in the Friedel-Crafts alkylation of indoles with alpha'-phosphoric enones. The enantioselectivities of this reaction are obtained in up to 98% ee.

Enantioselective Friedel-Crafts Alkylation of Indoles with Nitroalkenes

Enantioselective Friedel-Crafts Alkylation of Indoles with Nitroalkenes

Controllable enantioselective Friedel-Crafts reaction between indoles and alkylidene malonates catalyzed by pseudo-C3-symmetric trisoxazoline copperII complexes.

Pseudo-C(3)-symmetric trisoxazoline copper(II) complexes prove to be excellent catalysts in the Friedel-Crafts alkylation of indoles with alkylidene malonates. The absolute stereochemistry of this reaction is shown to be dependent on the solvent. Reactions in isobutyl alcohol afford the Friedel-Crafts alkylation adducts in excellent yields and with up to +98% ee. In 1,1,2,2-tetrachloroethane (TTCE), however, the opposite enantiomers of the products are obtained in good yields with up to -89% ee. Water tolerance of chiral catalyst trisoxazoline 2a/Cu(OTf)(2) is examined, and it is found that the addition of up to 200 equiv of water relative to catalyst in isobutyl alcohol has almost no effect on enantioselectivity but slows down the reaction. The reaction scope is studied as well. The roles of alcohol as the solvent to accelerate the reaction are discussed. The stereochemical models of asymmetric induction for reactions both in isobutyl alcohol and in TTCE are also developed.