Synlett 2022; 33(05): 440-457
DOI: 10.1055/s-0040-1719845
account

Synthesis of Purines and Related Molecules by Cyclization ­Reactions of Heterocyclic Enamines

Peter Langer
a   Institut für Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany
b   Leibniz-Institut für Katalyse e. V. an der Universität Rostock, ­Albert-Einstein-Str. 29a, 18059 Rostock, Germany
› Author Affiliations


Abstract

A great variety of pharmacologically relevant fluorinated purine analogues are available by cyclization reactions of heterocyclic enamines with 1,3-dielectrophiles. The reactions usually proceed with excellent regioselectivities. As electrophiles, 1,3-diketones, enaminones or 3-chloro-2-en-1-ones were used. Other synthetic strategies are based on inverse-electron-demand Diels–Alder reactions of heterocyclic enamines with triazines. Purine analogues were further functionalized by transition-metal-catalyzed CH-coupling reactions or oxidative cyclizations, giving rise to more complex polycyclic products. Amidino-C-glycosides in their reactions with 1,3-dielectrophiles afforded pyrimidine-C-glycosides. Multicomponent reactions of heterocyclic enamines afforded complex products, including spirocyclic derivatives.

1 Introduction

2 1,3-Diketones

3 Enaminones

4 3-Chloro-2-en-1-ones

5 Triazines

6 Transition-Metal-Catalyzed Functionalizations

7 Pyrimidine-C-Nucleosides

8 Multicomponent Reactions

9 Conclusions



Publication History

Received: 06 September 2021

Accepted after revision: 15 September 2021

Article published online:
22 October 2021

© 2021. Thieme. All rights reserved

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany