Magnesium halide-catalyzed hydroboration of isocyanates and ketones

Abstract

Alkaline-earth metal have attracted increasing attention because they are cheap, earth abundant and environmentally friendly, and gradually become an inexpensive and sustainable alternative to traditional precious transition metal catalysts in...

Magnesium(ii) complexes supported by indole- and pyrrole-containing Schiff-base ligands: syntheses, structures, and applications as precatalysts in the hydroboration of nitriles and alkynes

“…Earth-abundant main group-metal complexes offer nontoxic, inexpensive and sustainable alternatives to precious transition-metal catalysts in various synthetic transformations, especially in the hydroboration of carbon–heteroatom and carbon–carbon multiple bonds. 1–16 These hydroboration reactions represent a series of atom-economic processes for the preparation of boron-containing compounds. In these compounds, the boron-containing groups could serve as functional handles for synthesizing new C–C bonds or for transforming boron-containing groups into halogen, alcohol, amine and amide functionalities.…”

Mixed Lithium–Aluminum Hydrides Bearing Ar-Bian Ligands: Reactivity Toward Heteroallenes

“…So, the first examples of catalytic hydroboration of isocyanate by pinacolborane (HBpin) to form N , O -bis­(boryl)­hemaminals or N -borylmethyl amines were achieved by using β-diketiminato and hydridotriphenylborate magnesium complexes. Pioneer studies of the catalytic hydroboration of carbodiimides were carried out by Hill and Okuda, utilizing the same magnesium compounds. , Further studies have discovered a wide range of catalytic systems, including derivatives of transition metals, − main group elements, ,− or actinides, , that are able to catalyze these reactions. However, the hydroboration of isocyanates and carbodiimides typically results in the formation of mixtures of products.…”

Carbodiimide and Isocyanate Hydroboration by a Cyclic Carbodiphosphorane Catalyst**

“…[9,29] Subsequent work has revealed a range of catalysts for the selective hydrodeoxygenation of isocyanates at 50-100 °C. [24,[30][31][32][33][34][35][36][37][38] The monohydroboration of isocyanates has also been observed at long reaction times under catalyst-free conditions [35] or using transition metal, [12,33,35,39] main group, [23,24,30,32,34,38,40] and actinide [37] catalysts. However, notably, none of the existing catalysts for carbodiimide or isocyanate hydroboration are neutral, Lewis basic organocatalysts.…”