Synthesis of bromoindole alkaloids from Laurencia brongniartii.
A regioselective synthesis of N-carbomethoxy-2,3,5-tribromoindole (6) via a sequential one-pot bromination-aromatization-bromination of N-carbomethoxyindoline (2) is described. The process for the transformation of 2 into 6 permitted the isolation of stable reaction intermediates N-carbomethoxy-5-bromoindoline (3), N-carbomethoxy-5-bromoindole (4), and N-carbomethoxy-3,5-dibromoindole (5). Compound 6 was used to complete the total synthesis of the natural products 1b and 1c. In addition, bromination of N-carbomethoxyindole (11) afforded N-carbomethoxy-2,3,6-tribromoindole (13), from which the natural product 1a was synthesized.
Suárez-Castillo
Oscar R
OR
Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Hidalgo, Apartado 1-622, Pachuca, Hidalgo, 42001 México. osuarez@uaeh.edu.mx
Beiza-Granados
Lidia
L
Meléndez-Rodríguez
Myriam
M
Alvarez-Hernández
Alejandro
A
Morales-Ríos
Martha S
MS
Joseph-Nathan
Pedro
P
D018360:Crystallography, X-Ray; D006842:Hydrocarbons, Brominated / Q000138:chemical synthesis* / Q000737:chemistry; D026121:Indole Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D044722:Laurencia / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure
D006842:Hydrocarbons, Brominated; D026121:Indole Alkaloids