Trifluoromethylated alkynes (CF₃ alkynes) are among the most powerful synthetic intermediates for the preparation of ­fluorine-containing materials. In this account, our recent advances on the synthesis and reactions of trifluoromethylated alkynes are described. 1 Introduction 2 Synthesis of Trifluoromethylated Alkynes 3 Addition Reactions of H–M, C–M and M–M (M = Metal) with Trifluoromethylated Alkynes 3.1 Hydrostannation (H–Sn) 3.2 Hydroboration (H–B) 3.3 Hydrosilylation (H–Si) 3.4 Other Hydrometallations (H–Cu, H–Al) 3.5 Carbostannylation (C–Sn) 3.6 Carbocupration (C–Cu) 3.7 Carbopalladation (C–Pd) 3.8 Bisstannylation (Sn–Sn) 3.9 Silylstannylation (Si–Sn) 4 Cyclization Using Trifluoromethylated Alkynes 4.1 Synthesis of Trifluoromethylated Dihydroisoxazoles 4.2 Synthesis of Trifluoromethylated Indoles 4.3 Synthesis of Trifluoromethylated Benzofurans 4.4 Synthesis of Trifluoromethylated Isoquinolines 4.5 Synthesis of Trifluoromethylated Cyclopentenones 4.6 Synthesis of Trifluoromethylated Benzenes 5 Concluding Remarks

Fluorine-containing dissymmetric bistolanes were found to be promising light-emitting liquid crystals, which could switch luminescence depending on molecular aggregations.

In this study, we synthesized a series of fluorinated and non-fluorinated tolanes, in which one or more fluorine atoms were systematically introduced into one aromatic ring of a tolane scaffold, and systematically evaluated their photophysical properties. All the tolanes with or without fluorine substituents were found to have poor photoluminescence (PL) in tetrahydrofuran (THF) solutions. On the other hand, in the crystalline state, non-fluorinated and fluorinated tolanes with one or four fluorine atoms were less emissive, whereas fluorinated tolanes with three or five fluorine atoms exhibited high PL efficiencies (Ф_PL) up to 0.51. X-ray crystallographic analyses of the emissive fluorinated tolanes revealed that the position of the fluorine substituent played a key role in achieving a high Ф_PL. Fluorine substituents at the ortho (2/6) and para (4) positions led to tight and rigid packing due to plural π–π stacking and/or hydrogen bonding interactions, resulting in enhanced Ф_PL caused by the suppression of non-radiative deactivation. Additionally, fluorinated tolanes with three fluorine atoms exhibited notable aggregation-induced PL emission enhancement in THF/water mixed solvents. This demonstrates that the PL characteristics of small PL materials can be tuned depending on the usage requirements.

Unique tricyclic molecules bearing a CF₂CF₂-containing cyclohexa-1,3-diene motif were firstly synthesized and proved to show a large negative dielectric anisotropy.

Fluorinated tolanes were found to show aggregation-induced emission characteristics and significantly enhanced photoluminescence efficiencies in molecular aggregates when compared with non-fluorinated tolanes. The fluorine atoms play important roles in the formation of tight crystal packing structures to suppress molecular motion in the crystalline state via electrostatic or hydrogen bonding interactions.