Access to a variety of bulky phosphines remains critical to homogeneous catalyst development. CYTOP® 170 (4,8-dimethyl-2-phosphabicylo[3.3.1]nonane CAS: 328952-85-8 (Strem Catalog# 15-7605) represents a bulky cyclic phosphine ligand that can be derivatized to make a variety of mono- and bidentate ligands for homogeneous catalysis – and is available commercially. Based on the limonene molecule, this secondary phosphine acts as a bulky precursor for phosphine ligands for use in catalysis. Available from Solvay in commercial quantities and Strem in commercial sampling and research quantities, CYTOP® 170 (Strem Catalog# 15-7605) represents a unique and cost effective bulky phosphine ligand precursor for hydroformylation as well as coupling chemistry.
(Strem Catalog# 15-7605)
CYTOP® 170 (Strem Catalog# 15-7605) is used to synthesize hindered tertiary phosphine ligands via the addition of an olefin using free radical initiators (1). The P-H bond is easily accessible for chemical modification and as such, the chemical alteration via radical or other methods, proceeds readily. The resulting bulky tertiary phosphine ligands have been used for cobalt-catalyzed hydroformylation (2). In these cases, long alkyl chains, such as 1-octadecene can be added to form effective and unique hydroformylation phosphine ligands. Complexation of the derivatives to cobalt of the two resulting diastereomers did not result in radically different hydroformylation rates or selectivity.
CYTOP® 170 (Strem Catalog# 15-7605) can also be used to make bidentate phosphine ligands by its reaction with dihaloorganics, such as dibromo-ortho-xylene (3), the palladium complexes of these ligands finding utility as catalysts. CYTOP® 170 (Strem Catalog# 15-7605) has also been employed as a ligand in aryl chloride coupling reactions for C-C and C-N bond formation (Heck, Suzuki, Arylation, and Amination reactions) (4,5).
CYTOP® 170 (Strem Catalog# 15-7605) is a clear, colorless to pale yellow, air sensitive liquid. 4,8-Dimethyl-2-phosphabicyclo[3.3.1]nonane is a powerful reducing agent and must be handled under an inert atmosphere.
15-7605 4,8-Dimethyl-2-phosphabicyclo[3.3.1]nonane, min. 90%, CYTOP® 170