Diisobutylaluminum

Diisobutylaluminum refers to organoaluminum compounds in which aluminum is bonded to two isobutyl groups. As a class, these species are highly reactive and typically exist as solutions or as adducts with ethers or hydrocarbon solvents. The most prominent member is diisobutylaluminum hydride (DIBAL-H), with the formula (iBu)2AlH. DIBAL-H is a widely used reducing agent in organic synthesis, notable for its ability to reduce esters to aldehydes at low temperatures (for example, about -78°C) with careful stoichiometry, and for reducing nitriles to aldehydes under controlled conditions.

Other diisobutylaluminum reagents without hydride, such as dialkylaluminum species, can participate in hydroalumination reactions or act as Lewis acids in catalytic or stoichiometric systems, often as adducts with ethers (such as THF or diethyl ether) that stabilize the aluminum center.

Preparation and handling of diisobutylaluminum reagents are typically conducted under inert atmosphere because of their high reactivity toward moisture and air. They are usually used as solutions in hydrocarbon or ether solvents, and can form aggregates or adducts that affect reactivity. Safety concerns include violent reaction with water and oxygen, generating hydrogen gas and heat; handling requires dry solvents, proper ventilation, and appropriate protective equipment.

Applications extend beyond DIBAL-H reductions to other reactions in which dialkylaluminum species act as initiators, co-catalysts, or reagents in organic synthesis, though their use is often specialized compared with more common organoaluminum reagents.