������ Studies on the rhodium-catalyzed addition of alkynes to aldehydes and activated ketones are ongoing (eq. 1).� During the past grant period experiments to help define the mechanism and attempts to find an asymmetric variant have been the primary focus.� Numerous chiral phosphine ligands were used in an attempt to induce asymmetry to the process, but we have been unable to find a ligand system where high yield and enantioselectivity result using chiral phosphines.� Attempts to modify the b-diketonate ligand will also be explored.�

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������ The expansion of transition-metal catalyzed nucleophilic addition reactions to the Henry reaction was also explored.� Several literature reports describe metal complexes as excellent catalysts for the nitroaldol reaction.� These transformations appeared to be easily modified into asymmetric processes, and therefore a reinvestigation of this work was undertaken.

������ To facilitate ligand screening studies, attempts were made to generate the catalytically active metal complex in situ.� A combination of� [Rh(nbd)Cl]₂ (nbd = norbornadiene) and tri-n-butyl phosphine provided the desired nitroaldol product in 46% yield.� While this result appeared promising, use of tri-n-butyl phosphine alone gave a 91% yield, implicating the phosphine as the primary active catalyst.� Further studies revealed that many electron rich phosphines were excellent catalysts for the Henry reaction (eq. 2).� This study showed that care should be exercised in using metal-phosphine complexes as catalysts for the Henry reaction, as even small amounts of phosphine can lead to excellent yields of the nitroalcohol product.

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