TY - JOUR
T1 - Palladium-catalyzed selective and sequential functionalization of 2,4,6-trihalopyridine rings
T2 - Synthesis of ethynylpyridine polymers directly joined with aza-crown ethers
AU - Takashima, Shunsuke
AU - Yamamoto, Tsuyoshi
AU - Abe, Hajime
AU - Inouye, Masahiko
PY - 2011/12/22
Y1 - 2011/12/22
N2 - Meta-Ethynylpyridine polymer directly joined with 1-aza-18-crown-6 ether was synthesized by applying 2,4,6-trihalopyridines as a starting material. By using a Pd(OAc) 2-BINAP combination with an excess of Cs2CO3, 2,6-dichloro-4-iodopyridine could be condensed with 1-aza-18-crown-6 ether to afford 4-azacrown-substituted 2,6-dichloropyridine selectively. The two chlorine atoms of this product were replaced with ethynyl groups by copper-free Sonogashira reaction with tert-butyldimethylsilylacetylene followed by protiodesilylation. Subsequent steps involving Sonogashira reactions gave diiodo- and diethynyl- substituted tripyridine units, and their co-polymerization yielded the targeted polymer.
AB - Meta-Ethynylpyridine polymer directly joined with 1-aza-18-crown-6 ether was synthesized by applying 2,4,6-trihalopyridines as a starting material. By using a Pd(OAc) 2-BINAP combination with an excess of Cs2CO3, 2,6-dichloro-4-iodopyridine could be condensed with 1-aza-18-crown-6 ether to afford 4-azacrown-substituted 2,6-dichloropyridine selectively. The two chlorine atoms of this product were replaced with ethynyl groups by copper-free Sonogashira reaction with tert-butyldimethylsilylacetylene followed by protiodesilylation. Subsequent steps involving Sonogashira reactions gave diiodo- and diethynyl- substituted tripyridine units, and their co-polymerization yielded the targeted polymer.
UR - http://www.scopus.com/inward/record.url?scp=84862909344&partnerID=8YFLogxK
U2 - 10.3987/COM-11-S(P)62
DO - 10.3987/COM-11-S(P)62
M3 - 学術論文
AN - SCOPUS:84862909344
SN - 0385-5414
VL - 84
SP - 355
EP - 360
JO - Heterocycles
JF - Heterocycles
IS - 1
ER -