Huang, Chunhui published the artcileThe Pyridyldiisopropylsilyl Group: A Masked Functionality and Directing Group for Monoselective ortho-Acyloxylation and ortho-Halogenation Reactions of Arenes, Formula: C8H5IO, the publication is Advanced Synthesis & Catalysis (2011), 353(8), 1285-1305, database is CAplus and MEDLINE.
A novel, easily removable and modifiable silicon-tethered pyridyldiisopropylsilyl directing group for C-H functionalizations of arenes has been developed. The installation of the pyridyldiisopropylsilyl group can efficiently be achieved via two complementary routes using easily available 2-(diisopropylsilyl)pyridine (I). The first strategy features a nucleophilic hydride substitution at the silicon atom in I with aryllithium reagents generated in situ from the corresponding aryl bromides or iodides. The second milder route exploits a highly efficient room-temperature rhodium(I)-catalyzed cross-coupling reaction between I and aryl iodides. The latter approach can be applied to the preparation of a wide range of pyridyldiisopropylsilyl-substituted arenes possessing a variety of functional groups, including those incompatible with organometallic reagents. The pyridyldiisopropylsilyl directing group allows for a highly efficient, regioselective palladium(II)-catalyzed mono-ortho-acyloxylation and ortho-halogenation of various aromatic compounds Most importantly, the silicon-tethered directing group in both acyloxylated and halogenated products can easily be removed or efficiently converted into an array of other valuable functionalities. These transformations include protio-, deuterio-, halo-, boro-, and alkynyldesilylations, as well as a conversion of the directing group into the hydroxy functionality. In addition, the construction of aryl-aryl bonds via the Hiyama-Denmark cross-coupling reaction is feasible for the acetoxylated products. Moreover, the ortho-halogenated pyridyldiisopropylsilylarenes, bearing both nucleophilic pyridyldiisopropylsilyl and electrophilic aryl halide moieties, represent synthetically attractive 1,2-ambiphiles. A unique reactivity of these ambiphiles has been demonstrated in efficient syntheses of arylenediyne and benzosilole derivatives, as well as in a facile generation of benzyne. In addition, preliminary mechanistic studies of the acyloxylation and halogenation reactions have been performed. A trinuclear palladacycle intermediate has been isolated from a stoichiometric reaction between diisopropyl(phenyl)pyrid-2-ylsilane and palladium acetate. Furthermore, both C-H functionalization reactions exhibited equally high values of the intramol. primary kinetic isotope effect (kH/kD = 6.7). Based on these observations, a general mechanism involving the formation of a palladacycle via a C-H activation process as the rate-determining step has been proposed.
Advanced Synthesis & Catalysis published new progress about 69626-75-1. 69626-75-1 belongs to benzofurans, auxiliary class Iodide,Benzofuran, name is 2-Iodobenzofuran, and the molecular formula is C8H5IO, Formula: C8H5IO.
Referemce:
https://en.wikipedia.org/wiki/Benzofuran,
Benzofuran | C8H6O – PubChem