Synthesis 2020; 52(19): 2731-2760
DOI: 10.1055/s-0040-1707123
review
© Georg Thieme Verlag Stuttgart · New York

Pd-Catalyzed Domino Reactions Involving Alkenes To Access Substituted Indole Derivatives

Michael S. Christodoulou
a   DISFARM, Sezione di Chimica Generale e Organica ‘A. Marchesini’ Università degli Studi di Milano, via Venezian 21, 20133 Milano, Italy   Email: michail.christodoulou@unimi.it   Email: egle.beccalli@unimi.it   Email: sabrina.giofre@unimi.it
,
a   DISFARM, Sezione di Chimica Generale e Organica ‘A. Marchesini’ Università degli Studi di Milano, via Venezian 21, 20133 Milano, Italy   Email: michail.christodoulou@unimi.it   Email: egle.beccalli@unimi.it   Email: sabrina.giofre@unimi.it
,
Francesca Foschi
b   Dipartimento di Scienza e Alta Tecnologia, Università dell’Insubria, via Valleggio 11, 22100, Como, Italy   Email: francesca.foschi@uninsubria.it
,
Sabrina Giofrè
a   DISFARM, Sezione di Chimica Generale e Organica ‘A. Marchesini’ Università degli Studi di Milano, via Venezian 21, 20133 Milano, Italy   Email: michail.christodoulou@unimi.it   Email: egle.beccalli@unimi.it   Email: sabrina.giofre@unimi.it
› Author Affiliations
This work was supported by Università degli Studi di Milano under ‘Piano di sostegno alla ricerca 2019, Linea 2’ (annual allocation for institutional activities).
Further Information

Publication History

Received: 04 March 2020

Accepted after revision: 28 April 2020

Publication Date:
26 May 2020 (online)


Abstract

Palladium-catalyzed domino reactions are advanced tools in achieving various nitrogen-containing heterocycles in an efficient and economical manner due to the reduced number of steps in the process. This review highlights recent advances in domino processes aimed at the synthesis of indole derivatives and polycyclic systems containing the indole nucleus in intra/intra- or intra/intermolecular reactions. In particular, we consider domino processes that involve a double bond in a step of the sequence, which allow the issue of regioselectivity in the cyclization to be faced and overcome. The different sections in this review focus on the synthesis of the indole nucleus and functionalization of the scaffold starting from different substrates that have been identified as activated starting materials, which involve a halogenated moiety or unactivated unsaturated systems. In the former case, the reaction is under Pd(0) catalysis, and in the second case a Pd(II) catalytic species is required and then an oxidant is necessary to reconvert the Pd(0) into the active Pd(II) species. On the other hand, the second method has the advantage that it uses easy available and inexpensive substrates.

1 Introduction

2 Indole Scaffold Synthesis

2.1 Activated Substrates

2.2 Unactivated Substrates

3 Functionalization of Indole Scaffold

3.1 Activated Substrates

3.2 Unactivated Substrates

4 Conclusions