Catalyst Ligands and Ligand Intermediates

Offering CYTOP^® for a Variety of Uses

Over a ten year period from 1955 to 1965, American Cyanamid scientists carried out pioneering research in the field of phosphine chemistry. The technology developed form this research was the basis for a unique full scale manufacturing facility which began operation in 1971. Cytec, the former chemicals division of American Cyanamid, continues to operate this facility to produce phosphine, a wide variety of alkylphosphines as well as downstream products.

The high pressure phosphine technology employed at this facility allows Cytec to manufacture primary (RPH₂), secondary (R₂PH) and tertiary (R₃P) alkylphosphines. The latter find utility as catalyst ligands where as the primary and secondary alkylphosphines can be used as intermediates for example, the synthesis of asymmetric mono dentate ligands, RR’₂P, or bidentate ligands,  R₂P(-CH₂)_n-PR₂.

1,3,5,7-tetramethyl-2,4,8-trioxa-6-phenyl-6-phosphaadamantane (CYTOP^® 292) was first prepared by Epstein and Buckler in 1961. It is a highly efficient and very air stable and robust ligand for palladium catalyzed Heck and Suzuki reactions. Read more. (CYTOP 292 references).

Tertiary alkyl phosphines based on the 2-phosphabicyclo[3.3.1]nonane, 4,8-dimethyl bicyclic platform (CYTOP 170) are excellent ligands for olefin hydroformylation (CYTOP 170 references)

Tertiary alkylphosphines based on the well known “phobane” skeleton (CYTOP 198 and CYTOP 224) are also extremely efficient for hydroformylation and olefin metathesis (phobane ligand references).

Phosphorinones (CYTOP 228) and various reduction products thereof were originally prepared by Welcher and day in 1962 are another class of extremely hindered and consequently selective catalyst ligands which are useful for palladium catalyzed cross-coupling reactions (pherone ligand references)

Surprisingly, even certain hindered secondary phosphines such as CYTOP 222 or CYTOP 242 are excellent ligands for Heck coupling reactions (secondary phosphine ligand references).

Simple unhindered mono-dentate ligands such as CYTOP 320, CYTOP 340, CYTOP 341,  CYTOP 355 or CYTOP 380 find utility as ligands in a variety of applications such as  hydroformylation, hydrocarbonylation, hydrogenation, ruthenium catalyzed addition of thioamides to alkynes (mono dentate ligand references).

FeCl₃ when complexed with tertiary alkylphosphines such as CYTOP 340 are unique free radical sources for living polymerization reactions (free radical catalyst references).