TY - JOUR
T1 - Metal- and Protection-Free [4 + 2] Cycloadditions of Alkynes with Azadienes
T2 - Assembly of Functionalized Quinolines
AU - Saunthwal, Rakesh K
AU - Patel, Monika
AU - Verma, Akhilesh K.
PY - 2016/5/6
Y1 - 2016/5/6
N2 - A base promoted, protection-free, and regioselective synthesis of highly functionalized quinolines via [4 + 2] cycloaddition of azadienes (generated in situ from o-aminobenzyl alcohol) with internal alkynes has been discovered. The reaction tolerates a wide variety of functional groups which has been successfully extended with diynes, (2-aminopyridin-3-yl)methanol, and 1,4-bis(phenylethynyl)benzene to afford (Z)-phenyl-2-styrylquinolines, phenylnaphthyridine, and alkyne-substituted quinolines, respectively. The proposed mechanism and significant role of the solvent were well supported by isolating the azadiene intermediate and deuterium-labeling studies.
AB - A base promoted, protection-free, and regioselective synthesis of highly functionalized quinolines via [4 + 2] cycloaddition of azadienes (generated in situ from o-aminobenzyl alcohol) with internal alkynes has been discovered. The reaction tolerates a wide variety of functional groups which has been successfully extended with diynes, (2-aminopyridin-3-yl)methanol, and 1,4-bis(phenylethynyl)benzene to afford (Z)-phenyl-2-styrylquinolines, phenylnaphthyridine, and alkyne-substituted quinolines, respectively. The proposed mechanism and significant role of the solvent were well supported by isolating the azadiene intermediate and deuterium-labeling studies.
U2 - 10.1021/acs.orglett.6b00817
DO - 10.1021/acs.orglett.6b00817
M3 - Article (Academic Journal)
C2 - 27119774
SN - 1523-7060
VL - 18
SP - 2200
EP - 2203
JO - Organic Letters
JF - Organic Letters
IS - 9
ER -