In memory of Prof. Carlo Bonini
Abstract
This review gives an overview on recent developments in methods for the construction
of compounds with the 2,3-dihydrobenzofuran core in the period 2012 to 2019. Interest
in 2,3-dihydrobenzofurans is constantly increasing. The methods are divided into intermolecular
and intramolecular approaches. Intermolecular approaches are subdivided according
to the parent intermediate for the key reaction, while intermolecular approaches are
subdivided according by which bond is formed in the key reaction. The transformation
of benzofurans to dihydrobenzofurans and other miscellaneous methods are also discussed.
Approaches useful for the synthesis of natural products are emphasized.
1 Introduction
2 Intermolecular Approaches
2.1 o-Quinone Methides and o-Quinones
2.2 p-Quinone Methides and p-Quinones
2.3 Nitrogen-Containing Phenols and Quinones
2.4 o-Hydroxyphenylcarbonyl Derivatives and Phenols
2.5 Miscellaneous
3 Intramolecular Approaches
3.1 O–C2 Bond Forming
3.2 C2–C3 Bond Forming
3.3 C3–Aryl Bond Forming
3.4 O–Aryl Bond Forming
4 From BF to DHB
5 Rearrangements and Aromatizations
Key words
dihydrobenzofurans - cyclizations - natural products - carbenes - nucleophiles -
stereoselective synthesis
