Asymmetric Friedel-Crafts alkylations of indoles with dialkyl 3-oxoprop-1-enylphosphonates: organocatalytic enantioselective synthesis of alpha-indolyl phosphonates.

Organocatalytic enantioselective synthesis of alpha-indolyl phosphonates has been successfully carried out via asymmetric Friedel-Crafts alkylation of substituted indoles with (E)-dialkyl 3-oxoprop-1-enylphosphonates in 48-82% yield and 73-96% ee.

Dimethyl [1-(1-allyl-5-iodo-1H-indol-3-yl)-3-hydroxy-prop-yl]phospho-nate.

In the title compound, C(16)H(21)INO(4)P, the mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O hydrogen-bond inter-action. The crystal packing is stabilized by strong inter-molecular O-H ⋯ O hydogen-bonding inter-actions to form a zigzag packing arrangement.

Organocatalytic C3-selective Friedel-Crafts alkylations of indoles with alpha,beta-unsaturated ketones.

The use of an equimolar amount of pyrrolidine and HClO4 (30 mol%) was found to be effective in promoting the conjugate addition of indoles to (E)-alpha,beta-unsaturated ketones, affording the corresponding beta-indolyl ketones in excellent yields.

Highly efficient route to functionalized tetrahydrocarbazoles using a tandem cross-metathesis/intramolecular-hydroarylation sequence.

The scope of the novel ruthenium-catalyzed tandem cross-metathesis/intramolecular-hydroarylation sequence is described. This methodology offers a practical and efficient synthesis of structurally diverse and complex tetrahydrocarbazoles in good to excellent yields (up to 98%). Moreover, preliminary efforts towards the development of an enantioselective version of the current process by sequential catalysis with ruthenium complex and chiral amine are presented, with high yields and enantioselectivities (up to 88% yield and 91% ee).