Aromatic alkynes are active intermediates formed by the partial overlap of sp2 orbitals of two carbon atoms ortho to an aromatic ring. This structure can efficiently achieve ortho difunctionalization of aromatic rings. For example, the currently widely used Kobayashi aryne precursor can functionalize two groups at the 1,2-position of the benzene ring. Is it possible to achieve trifunctionalization of aromatic rings through aromatic alkynes?

Professor Li Yang of Chongqing University has developed a new domino aryne precursor - TPBT, which can functionalize three different groups at the 1, 2, and 3-positions of the benzene ring through a continuous domino process to achieve multi-functionality of aryne in one step change!

TPBT reagent can be activated by F- or CO32- under mild conditions to release domino arylyne intermediates (as shown in Figure 1). This mild activation condition enables the TPBT reagent to have broad functional group compatibility and can be used in a variety of reaction types. TPBT reacts with different nucleophiles and electrophiles to obtain a variety of 1,2,3-trisubstituted benzene derivatives, and can also prepare 1,3- and 1,2-amphiphilic reaction products.

Figure 1. Structure of TPBT and its aromatic alkyne intermediates

Features:

Used for a variety of reaction types, with mild reaction conditions and broad functional group compatibility;
The 1, 2, and 3-position functionalization of the benzene ring can be achieved.

Sulfonate-protected aromatic amines and TPBT reagents can generate different compounds under different activators [1].

Qiu, D.; He, J.; Yue, X.; Shi, J.; Li, Y. Diamination of Domino Aryne Precursor with Sulfonamides. Org. Lett. 2016, 18, 3130-3133.