Abstract
The discovery of new asymmetric synthetic methodologies and the asymmetric synthesis
of new chiral compounds have been a major focus of synthetic organic chemists for
decades. Axially chiral compounds have gained considerable attention in recent years
because of their widespread utility in asymmetric catalysis and synthesis. Methods
for the asymmetric synthesis of axially chiral cycloalkylidenes, a subset of axially
chiral molecules, are far fewer compared to those developed for the preparation of
chiral allenes and chiral biaryl compounds. In this review, different approaches for
the synthesis of axially chiral cycloalkylidenes are summarized.
1 Introduction
2 Methods for the Enantioselective Synthesis of Axially Chiral Cycloalkylidenes
2.1 Asymmetric Synthesis of Axially Chiral Cycloalkylidenes
2.1.1 Asymmetric Horner–Wadsworth–Emmons (HWE) Reactions
2.1.2 Asymmetric Wittig Reactions
2.1.3 Asymmetric Dehydrohalogenation Reactions
2.1.4 Asymmetric Elimination Reactions of Chiral Sulfoxides/Selenoxides
2.1.5 Kinetic Resolution of Prochiral Compounds
2.1.6 Other Miscellaneous Methods
2.2 Catalytic Asymmetric Synthesis of Axially Chiral Cycloalkylidenes
3 Conclusion
Key words
chiral cycloalkylidenes - asymmetric synthesis - asymmetric Wittig-type reaction -
chiral auxiliary - kinetic resolution - chiral cyclohexadienoxime
