Weak Base-Promoted Direct Cross-Coupling of Naphthalene-1,8-diaminato-substituted Arylboron Compounds.

The indispensability of a base in Suzuki-Miyaura coupling (SMC) employing organoboronic acids/esters is well recognized, which occasionally induces competitive protodeborylation in organoboron reagents. This phenomenon is particularly pronounced in fluorine-substituted aryl and heteroaryl boron compounds. Here, we show that direct SMC of naphthalene-1,8-diaminato (dan)-substituted aryl boron compounds, Ar-B(dan), characterized by its remarkable stability toward protodeborylation due to their diminished boron-Lewis acidity, occurs utilizing a weak base in conjunction with a palladium/copper cooperative catalyst system.

Surefire generation of stannylpotassium: highly reactive stannyl anions and applications.

Organometallic reagents such as organolithium and Grignard reagents have long been esteemed in chemical synthesis for their exceptional reactivity. In contrast, the application of their sodium and potassium counterparts has been comparatively sluggish, notwithstanding their augmented reactivity stemming from their heightened ionic character. This inertia persists due to the constrained accessibility of these heavy alkali metal reagents.

Ethynyl-B(dan) in [3+2] Cycloaddition and Larock Indole Synthesis: Synthesis of Stable Boron-Containing Heteroaromatic Compounds.

The cycloaddition of nitrile oxides with ethynyl-B(dan) (dan=naphthalene-1,8-diaminato) allowed the facile preparation of diverse isoxazolyl-B(dan) compounds, all of which displayed excellent protodeborylation-resistant properties. The dan-installation on the boron center proves vital to the high stability of the products as well as the perfect regioselectivity arising from hydrogen bond-directed orientation in the cycloaddition. The diminished boron-Lewis acidity of ethynyl-B(dan) also renders it amenable to azide-alkyne cycloaddition, Larock indole synthesis and related heteroannulations.