Synthesis 2021; 53(23): 4375-4388
DOI: 10.1055/a-1545-6874
short review

Recent Advance in Iminyl Radical Triggered C–H and C–C Bond Functionalization of Oxime Esters via 1,5-HAT and β-Carbon Scission

Le Liu
,
Xin-Hua Duan
,
Li-Na Guo
L. Liu thanks the National Natural Science Foundation of China (21901199) and Xi’an Jiaotong University (7121192002) for financial support. L.-N. Guo thanks the National Natural Science Foundation of China (21971201) for financial support.


Abstract

The direct functionalization of C(sp3)–H and C(sp3)–C(sp3) bonds is considered as one of the most valuable synthetic strategies because of its high efficiency and step-economy for the rapid assembly of complex molecules. However, the relatively high bond disassociation energies (BDEs) and similar chemical environment lead to large obstacles in terms of low reactivity and selectivity. Using a radical-based strategy has proved to be an efficient approach to overcome these difficulties via a hydrogen atom transfer (HAT) process for selective C(sp3)–H functionalization and β-carbon scission for C(sp3)–C(sp3) bond derivatization. Oxime esters have emerged as outstanding precursors of iminyl radicals for versatile chemical transformations. This short review summaries the recent advances in site-specific C(sp3)–H functionalization and C(sp3)–C(sp3) bond cleavage starting from oxime esters by our group and pioneering work by others, mainly focusing on the reaction design as well as the reaction mechanism.

1 Introduction

2 C(sp3)–H Bond Functionalization via 1,5-HAT of Acyclic Oxime Esters­

2.1 1,5-HAT/Cyclization

2.2 1,5-HAT/C–C or C–Heteroatom Bond Formation

3 C(sp3)–C(sp3) Bond Functionalization via β-Carbon Scission of Cyclic Oxime Esters

3.1 β-Carbon Scission/C–C or C–Heteroatom Bond Formation

3.2 β-Carbon Scission/Cyclization

4 Conclusion and Outlook



Publication History

Received: 26 May 2021

Accepted after revision: 07 July 2021

Accepted Manuscript online:
07 July 2021

Article published online:
19 August 2021

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