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Rare-earth silylamides serve as good catalysts for monoinsertion of isocyanides into terminal alkynes in the presence of amine additives, leading to 1-aza-1,3-enyens in excellent yields. Mechanistic investigation reveals that the amine additives play an important role as proton sources to prevent the oligomerization of isocyanides and as suitable ligands to activate the rare earth catalysts.

Regio- and stereoselective dimerization of terminal alkynes to produce conjugated enynes are achieved using rare-earth silylamide catalysts and amine additives. Dimerization of aromatic terminal alkynes, followed by hydrophosphination with diphenylphosphine enables highly efficient synthesis of 1-phosphinyl-1,3-butadienes in one-pot using single rare-earth catalysts.

Research has been conducted on the acylphosphonates and carbonyl compounds couplings that lead to beta-hydroxyphosphonates. The use of low-valent samariums is discussed.

Researchers have discovered the usefulness of ytterbium as a catalyst for achieving good yields of aminosilanes. This was achieved through the dehydrogenative silylation of primary and secondary amines with triphenysilane using ytterbium as a major catalyst. In the past, such chemical transformations were catalyzed using trivalent lanthanocene complexes, which were later found to be difficult for shipping, handling and large-scale synthesis.

A study was conducted to analyze the catalytic dehydrogenative silylation of terminal alkynes supporting hydrosilanes using divalent ytterbium-imine complexes. During the reaction of dihydrosilanes, the product distribution was obtained based on the ratio of 1-hexyne to the silanes. The reactivities of different monohydrosilanes were also evaluated. Results indicated the effectiveness of using ytterbium-imine catalysts in the dehydrogenative silylation of terminal alkynes supporting hydrosilane.

Bond fission of the C-O bond of allylic benzyl ethers with Cp*2Sm(thf)n produced samarium complexes in good yields. Ease of cleavage was observed to be comparable to the corresponding propargylic ethers intermolecularly, but lower intramolecularly. Regio- and stereochemistry on the electrophilic trappings of the allylic complexes produced were dependent on the type of electrophiles. They reacted with carbonyl compounds exclusively from the most substituted terminus of the allylic moieties to produce blanched homoallylic alcohols with anti-diastereoselectivity.

Research has been conducted on alkynes. The authors describe the intermolecular hydrophosphination of these compounds with diphenylphosphine catalyzed by ytterbium-imine complex to produce phosphine oxides and alkenylphosphines.

Intermolecular hydrophosphination of alkynes with diphenylphosphine is catalyzed by a Yb[bond]imine complex, [Yb(eta(2)-Ph(2)CNPh)(hmpa)(3)], to give alkenylphosphines and phosphine oxides after oxidative workup in good yields under mild conditions. This reaction is also applicable to various carbon[bond]carbon multiple bonds such as conjugated diynes and dienes, allenes, and styrene derivatives. Regio- and stereoselectivity and the scope and limitation of the present reaction clearly differ from those of the corresponding radical reaction. Instead, the reaction takes place through insertion of alkynes to a Yb[bond]PPh(2) species, followed by protonation. In fact, the Yb[bond]phosphido complex, [Yb(PPh(2))(2)(hmpa)(3)], is obtained from the imine complex and phosphine, which exhibits similar catalyst activity for the hydrophosphination. The empirical rate law is nu = k[catalyst](2) [alkyne](1)[phosphine](0) at least under the standard conditions.