A Synthesis of 3,4-Dihydroisoquinolin-1(2H)-one via the Rhodium-Catalyzed Alkylation of Aromatic Amides with N-Vinylphthalimide

Abstract

The alkylation of C–H bonds with N-vinylphthalimide by a rhodium-catalyzed reaction of aromatic amides containing an 8-aminoquinoline moiety as the directing group is reported. N-Vinylphthalimide functions as a 2-aminoethylating reagent. The resulting alkylated products can be converted into 3,4-dihydroisoquinolin-1­(2H)-one derivatives in a one-pot transformation. Deuterium-labeling experiments suggest that the reaction proceeds through a carbene mechanism.

Iron‐Catalyzed Ortho‐Selective C−H Alkylation of Aromatic Ketones with N‐Alkenylindoles and Partial Indolylation via 1,4‐Iron Migration

“…Yoshikai and co‐workers reported cobalt‐catalyzed C−H alkylation of aromatic imines with 9‐vinylcarbazole . Chatani and co‐workers also found the rhodium‐catalyzed C−H alkylation of benzamide derivatives with N ‐vinylphthalimide …”

Beyond Friedel and Crafts: Directed Alkylation of C−H Bonds in Arenes

“…The versatility of this directing group, therefore, compensates to some extent the loss of molecular weight inherent with its cleavage. This alkylation was later extended to the use of conjugated esters, styrenes, dihydrofurans, and unsaturated γ‐lactones as well as maleimides and N ‐vinylphthalimide in the presence of a rhodium catalyst. An alternative and quite versatile catalytic system based on an iron catalyst was also recently reported by the Ilies/Nakamura group …”

Rhodium‐Catalyzed Alkylation of C−H Bonds in Aromatic Amides with Non‐activated 1‐Alkenes: The Possible Generation of Carbene Intermediates from Alkenes

“…We recently reported on the Rh‐catalyzed reaction of aromatic amides that contain an 8‐aminoquinoline directing group with activated alkenes, such as acrylic esters, styrenes, α,β‐unsaturated lactones, maleimide, norbornene and N ‐vinylphthalimide . In a different system employing a picolinamide auxiliary, we described the alkylation reaction at C8‐position of 1‐naphthylamide using various alkenes .…”