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Titanium‐Catalyzed, One‐Pot Synthesis of 2‐Amino‐3‐cyano‐ pyridines
Author(s) -
Dissanayake Amila A.,
Staples Richard J.,
Odom Aaron L.
Publication year - 2014
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.201301046
Subject(s) - chemistry , tautomer , malononitrile , regioselectivity , catalysis , pyridine , alkyne , medicinal chemistry , ring (chemistry) , titanium , combinatorial chemistry , nitrile , organic chemistry
Abstract Earth‐abundant and inexpensive titanium can catalyze alkyne iminoamination, which generates tautomers of 1,3‐diimines. Upon treatment with base (DBU) and malononitrile, the multicomponent coupling product is converted to 2‐amino‐3‐cyanopyridines in a one‐pot procedure in good to modest yields. There is substantial control of regioselectivity for the substituents on the pyridine ring and on the 2‐amino group. Several studies were done that provide significant evidence for a Dimroth rearrangement mechanism for 2‐aminopyridine formation, including isolation of a 2‐imino‐1,2‐dihydropyridine intermediate that undergoes rearrangement under the reaction conditions.