Palladium- or iridium-catalyzed allylic substitution of guanidines: convenient and direct modification of guanidines.
As a convenient and direct functionalization of guanidines, the transition metal-catalyzed allylic substitution of guanidines was studied. The guanidine derivatives bearing two electron-withdrawing substituents acted as reactive nucleophiles in the allylic substitution to give the monoallylated products. The double allylic substitution was achieved by using tri-Boc-guanidine bearing three electron-withdrawing substituents as a nucleophile to give the diallylated products. The regiocontrol in the allylic substitution of unsymmetrical allylic substrates has been investigated by employing the palladium or iridium catalysts. The iridium complex of chiral pybox ligand allowed the regio- and enantioselective allylic substitution. Asymmetric double allylic substitution of tri-Boc-guanidine with phosphate bearing the 1-naphthyl group gave the diallylated product with high diastereo-, regio-, and enantioselectivities.
Miyabe
Hideto
H
Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan. miyabe@huhs.ac.jp
Yoshida
Kazumasa
K
Reddy
Valluru Krishna
VK
Takemoto
Yoshiji
Y
D000498:Allyl Compounds / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D006146:Guanidines / Q000138:chemical synthesis* / Q000737:chemistry; D007495:Iridium / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
D000498:Allyl Compounds; D006146:Guanidines; D009942:Organometallic Compounds; D007495:Iridium; D010165:Palladium