Readily Accessibleβ‑Ge-Substituted Amine-Boraneswith Enhanced Fluorescence Efficiency

The hydroboration of 2-pyridyl-substituted alkynylgermanes with 9-borabicyclo[3.3.1]nonane (9-BBN) produces a series of vinylboranes containing N–B coordination. In contrast to their alkynylsilane counterparts, this reaction involves migration of the germyl group. These intramolecular amine-boranes with substitution exclusively at the β-position exhibit significantly strong blue fluorescence and show enhanced fluorescence efficiency compared to previously reported analogues with α-substitution.