A transition-metal-free three-component process that combines aldehydes, 3-(tributylstannyl)­propargyl acetates formed in situ from readily available propargyl acetates, and trialkylboranes provides access to a range of 1,2,4-trisubstituted homopropargylic alcohols. The addition of diisopropylamine plays a crucial role in the selective formation of homopropargylic alcohols. Importantly, this methodology can be extended to a single-flask reaction sequence starting from propargyl acetates.

The trialkylborane/O2-mediated reaction of propargyl acetates having a tributylstannyl group at an alkyne terminus with aldehydes in a THF–H2O solvent system gave anti-δ,δ-disubstituted homoallylic alcohols with good to high diastereoselectivity. Intriguingly, two alkyl groups derived from trialkylborane were embedded into the reaction product. The trialkylborane plays a key role not only as a radical initiator but also as a source of alkyl radicals.

A synthesis of (Z)-alkene-containing linear conjugated dienyl homoallylic alcohols by using a palladium-catalyzed three-component reaction has been developed. This method shows good functional-group compatibility and generality, with high diastereoselectivity. Additionally, in many cases, the present method controls the alkene stereochemistry of the newly formed C–C bond and overcomes the inherent preference for (E)-alkene formation, giving (Z,E)- and (Z,Z)-products.

The diastereoselective synthesis of antihomoallylic alcohols bearing conjugated (Z)-enynes through a palladium-catalyzed three-component reaction is described. This reaction features a broad substrate scope, good functional group compatibility, and high levels of (Z)-alkene stereocontrol. In this reaction, Pd(0) functions as a catalyst in two fundamental steps of the tandem sequence: 1) the generation of a borylated π-allylpalladium species from bifunctional conjunctive reagents, inducing umpolung allylation of aldehydes, and 2) C(sp 2 )À C-(sp) cross-coupling. Further transformations of the obtained products highlight their synthetic utility.

A facile, efficient, and metal–free single-flask procedure for the synthesis of trisubstituted furans from simple readily available homopropargylic alcohols is described. The combination of Dess–Martin periodinane (DMP), H2O, and p-TsOH·H2O plays a crucial role in trisubstituted furans formation. The advantages of this method include operation ease, mild reaction conditions, and good functional-group tolerance.