Synthesis, Structure, and Reaction of a New Anionic Boron Nucleophile 'Boryllithium' and Its Application to the Synthesis of Boryl Transition Metal Complex

摘要

For most of the 2nd row p-block elements, fluorine, oxygen, nitrogen, and carbon, anionic species are known as a lithium salt, such as lithium fluoride (LiF), lithium alkoxide (ROLi), lithium amide (R_2NLi). and alkyllithium (R_3CLi). However, still there have been no direct observation of the lithium salt of anionic boron atom, boryllithium (R_2BLi). Since 1952, three examples have been reported assuming the existence of alkali metal salts of boryl anion as reactive intermediates, but none of them succeeded in spectroscopic characterization or isolation of the boryl anions. Herein, we report the synthesis of boryllithium 2, its structural and NMR spectroscopic analysis, and its application to the syntheses of boryl transition-metal complexes.