Synthesis of Phthalides and 3,4-Dihydroisocoumarins Using the
Palladium-Catalyzed Intramolecular Benzannulation Strategy
Taishi Kawasaki
Shinichi Saito
Yoshinori Yamamoto
10.1021/jo016336o.s001
https://acs.figshare.com/articles/journal_contribution/Synthesis_of_Phthalides_and_3_4-Dihydroisocoumarins_Using_the_Palladium-Catalyzed_Intramolecular_Benzannulation_Strategy/3692817
A novel method for the synthesis of phthalides and 3,4-dihydroisocoumarins via the palladium-catalyzed <i>intramolecular</i> benzannulation of bis-enyne and enyne−diyne systems is described.
Various kinds of substituted phthalides <b>9</b> and <b>17</b> and 3,4-dihydroisocoumarins <b>19</b> were synthesized
from <b>8</b>, <b>16</b>, and <b>18</b>, respectively, in moderate to excellent yields. The benzannulation reaction
proceeded chemoselectively to give the corresponding fused ring compounds <b>A</b> without the formation
of the regioisomeric products <b>B</b> (eq 6). Furthermore, this methodology was applied to the synthesis
of biologically active 3-<i>n</i>-butylphthalide <b>23</b>.
2002-03-22 00:00:00
formation
Strategy
intramolecular
Benzannulation
eq
regioisomeric products B
enyne
synthesis
benzannulation reaction
Dihydroisocoumarin
Various kinds
ring compounds
phthalides 9
yield
Phthalide
Intramolecular
novel method
methodology
butylphthalide 23
dihydroisocoumarin
Synthesi
chemoselectively