Abstract
The design and synthesis of spirocycles is a challenging task
because it involves the creation of a quaternary center, which itself
is considered to be one of the most difficult tasks among synthetic
transformations. Some recent approaches based on metathesis, cycloaddition
and transition-metal-mediated transformations to spirocycles are
described here.
1 Introduction
2 Scope of the Review
3 Alkylation Methods
4 Transition-Metal-Based Approaches
5 Rearrangement-Based Approaches
6 Ring-Expansion Method
7 Ring-Contraction Method
8 Photochemical Approaches
9 Ring Closure of Geminally Disubstituted Compounds
10 Cycloaddition Tactics
11 Other Cyclization Methods
12 Metathesis Approaches
13 Pauson-Khand Reaction
14 Conclusions and Future Prospects
Key words
spiro compounds - metathesis - Diels-Alder
reactions - domino reactions - Suzuki coupling - radical reactions - ring closure
