Fused-Ring Bulky “Rind” Groups Producing New Possibilities in Elemento-Organic Chemistry

Kinetic stabilization with sterically bulky substituents or ligands has played a pivotal role in exploring a large variety of unsaturated compounds or low-coordinated complexes. This article describes our findings that a series of fused-ring octa-R-substituted s-hydrindacenyl groups (Rind groups), which we developed since 2007, can act as unique protecting groups both in main group chemistry and in transition-metal chemistry. The synthesis, structures, and properties of various types of highly reactive unsaturated and low-coordinated element-organic compounds of Groups 1, 2, 8, 11, and 13–17 featuring the bulky Rind groups are covered.