Premium
2‐[(Neopentyl glycolato)boryl]phenyl Triflates and Halides for Fluoride Ion‐Mediated Generation of Functionalized Benzynes
Author(s) -
Ikawa Takashi,
Yamamoto Rika,
Takagi Akira,
Ito Toyohiro,
Shimizu Kazunori,
Goto Masahiko,
Hamashima Yoshitaka,
Akai Shuji
Publication year - 2015
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201500315
Subject(s) - aryne , chemistry , borylation , halide , fluoride , halogenation , medicinal chemistry , electrophile , structural isomer , functional group , combinatorial chemistry , organic chemistry , catalysis , aryl , inorganic chemistry , alkyl , polymer
Abstract 2‐[(Neopentyl glycolato)boryl]phenyl trifluoromethanesulfonates (triflates) and halides have been developed as new benzyne precursors, which generate benzynes at 120 °C in the presence of a fluoride ion. There are two major features of these types of precursors. First, they generate benzynes bearing various reactive functional groups, such as carbonyl, cyano, bromo, and primary amino groups. Second, these precursors were directly synthesized through either the palladium‐catalyzed Miyaura borylation of 2‐iodophenol derivatives or ortho ‐selective iodination of the corresponding boronic acids as key steps without using any protecting groups. The in‐situ ‐generated benzynes underwent [4+2], (3+2), and [2+2] cycloadditions to give the benzo‐fused multicyclic compounds while maintaining such functional groups. In particular, 4‐aminobenzyne was generated for the first time and underwent the Diels–Alder reaction with the free primary amino group remaining intact.