Syntheses of Nitrogen Heterocycles from Pyridines

Syntheses of Nitrogen Heterocycles from Pyridines Christopher D. Vanderwal, Department of Chemistry, University of California–Irvine substituted indoles with propenal group at C3

Suzuki coupling

R1

R

R1

CHO

BrCN, EtOH/H2O

X

R

63–87% yield NH2

X

N H

N

H2O R1

R = 4-OMe, 5-OMe, 4-CF3, 5-CF3, 4-F, 5-Cl, 6-Br R1 = H, Me X = CH, N

BrCN

R

N R X

N H

R1

R1

CN

R1

X R H2N

N

X Br

N H

CN

R

N

X

CN

N H

N

CN

6π retro electrocyclization, or expulsion of the electron-deficient cyanamide followed by tautomerization R1O

CONR2

H

Cl NO2

NO2

NHBz

N

n-BuOH, 100 °C

HN

NHBz

Me2NH (4 equiv.) EtOH, 50 °C N Ar

Cl

then NaOH/H2O 57% yield, 2 steps

CHO N Bz

dihydropyrrole core of porothramycins

N

X O Y

porothramycin A : R=Me, R1=H, X=OMe, Y=H porothramycin B : R=Me, R1=Me, X=OMe, Y=H anthramycin : R=H, R1=Me, X=OH, Y=Me