A new lanthanum-based catalyst was shown to be effective for the double hydrophosphinylation of unactivated nitriles under very mild conditions. Surprisingly, the lanthanum catalyst gave two regioisomeric products depending on the nature of the starting nitrile. Primary alkyl nitriles undergo 1,1-addition to give products with a new P–C–P linkage and concomitant formation of a primary amine. Under the same conditions, secondary alkyl and aryl nitriles instead produced 1,2-addition products, where 1 equiv of the phosphine oxide was added to the carbon, while a second equivalent added to the nitrogen of the nitrile, resulting in a P–C–N–P framework. Further investigation of the catalytic cycle yielded evidence that all nitriles first undergo 1,1-addition (deemed the kinetic product) that then undergoes isomerization to the final unsymmetric addition product (the thermodynamic product). All catalytic reactions were run neat or with very little solvent, required little workup, and had high to moderate yields.

A lanthanum-based N,N-dimethylbenzylamine complex was used as a precatalyst for both hydrophosphination and hydrophosphinylation of alkynes under mild conditions. In the case of hydrophosphination, the catalyst induced monoaddition with high regiospecificity, yielding only the anti-Markovnikov product, and stereoselectivity that could be controlled on the basis of the reaction conditions. Undertaking the catalysis with excess phosphine yielded the E isomer as the major product; however, using excess alkyne, the Z isomer was instead isolated as the major product. A brief investigation into the catalytic cycle suggested that a dimeric form of the lanthanum phosphide active catalyst provided the Z isomers as kinetic products that then underwent isomerization to yield the final E isomers. In the case of hydrophosphinylation, the chemoselectivity depended on the nature of the alkyne used. Terminal alkynes gave only double addition products while both single and double addition products were successfully isolated in the case of internal alkynes. The hydrophosphinylation also showed high chemo- and regioselectivity as only the anti-Markovnikov products were isolated. Monohydrophosphinylation of internal alkynes gave almost exclusively the E isomer, and double hydrophosphinylation of all alkynes led to 1,2-addition products.