Palladium-Catalyzed 1,1-Alkynyloxygenation of 2-Vinylbenzoates with Alkynyl Bromides

Abstract

The palladium-catalyzed reaction of alkyl 2-vinylbenzoates with silyl-protected alkynyl bromides leads to the selective production of 3-alkynylated isochroman-1-ones. The use of an alkyl ester group as an effective oxygen nucleophile is crucial for the efficient 1,1-alkynyloxygenation of alkenes.

Synthesis of Phenanthrenes and 1-Hydroxyphenanthrenes via Aromatization-Assisted Ring-Closing Metathesis: toward Polynuclear Aromatic Hydrocarbons

“…Initially, to examine our hypothesis, we used commercially available 1-bromo-2-naphthaldehyde (4) as our starting material. C-Vinylation of 4 with vinyl trifluoroborate, 16 catalyzed by Pd(OAc) 2 in the presence of PPh 3 and Cs 2 CO 3 Scheme 1. Literature Reports and Our Strategy for the Synthesis of Phenanthrene Derivatives Scheme 2.…”

“…Initially, to examine our hypothesis, we used commercially available 1-bromo-2-naphthaldehyde ( 4 ) as our starting material. C-Vinylation of 4 with vinyl trifluoroborate, catalyzed by Pd­(OAc) 2 in the presence of PPh 3 and Cs 2 CO 3 in THF-H 2 O at 85 °C, provided 1-vinyl-2-naphthaldehyde ( 3a ) in a 93% yield (Scheme ). Since 1-bromo-2-naphthaldehyde derivatives are not commercially available, they were synthesized from the corresponding α-tetralone derivatives by the Arnold–Vilsmeier reaction and sequential DDQ-assisted aromatization (Schemes S1 and S2 in Supporting Information).…”