Synthesis
DOI: 10.1055/s-0043-1775377
short review

Recent Advances in Saturated N-Heterocycle C–H Bond Functionalization for Alkylated N-Heterocycle Synthesis

,
Laurel L. Schafer
The authors thank the University of British Columbia (UBC), Natural Sciences and Engineering Research Council of Canada (NSERC), and the Canada Research Chairs program for funding. CHMZ thanks UBC and NSERC for graduate scholarships.


Abstract

The prominence of saturated N-heterocycle motifs in pharmaceuticals is undeniable. Challenges associated with the alkylation of saturated N-heterocycle scaffolds to efficiently access new drug analogues are hampered by synthetically laborious routes. Stereocontrolled alkyl-substitutions onto saturated N-heterocycles are particularly difficult to access in high yields by traditional synthetic methods. Alternatively, C–H bond functionalization provides a new and powerful synthetic avenue by directly and selectively functionalizing/alkylating/ arylating the abundantly available C–H bonds of saturated N-heterocycles. This review highlights complementary methods for directly activating and functionalizing C–H bonds of saturated N-heterocycles chemo-, regio-, and or stereoselectively to access alkylated products. This synthetic challenge has required catalyst development to access useful N-heterocyclic building blocks or for late-stage functionalization. Early transition metal, late transition metal, photoredox, and electrochemical methods are discussed. The selective functionalization of α, β, and γ C–H bonds to form new C–C, C–N, C–O, and C–B bonds is presented.

1 Introduction

2 Early Transition Metal Catalyzed α-Alkylation

3 Late Transition Metal Catalyzed α-Functionalization

4 Photoredox-Catalyzed α-Functionalization

5 Electrochemical α-Functionalization

6 C–H Functionalization of β and γ C–H Bonds

7 Conclusions/Outlook



Publication History

Received: 24 April 2024

Accepted after revision: 29 May 2024

Article published online:
01 August 2024

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