Tricyclohexylphosphine adduct

In the presence of tricyclohexylphosphine, Ni-diene condensations form Cg-containing ( -bis(a]lyl) complexes. Treatment of the tricyclohexylphosphine adduct of (cyclododecatriene)Ni with 1,3-dienes affords thermally stable complexes having the stoichiometry Ni(diene)2P(C6Hu)3 From IR and NMR studies and the structure of the isoprene derivative , these complexes contain the S)j -bis(allyl) structure, both in the solid state and in solution ... 

The reaction of isoprcnc with Et NH in the presence of triethylammonium iodide (10 mol%) gives the 1 1 adducts 51 and 52 with high selectivity(53]. The reaction of isoprene with ammonia or diethylamine affords the tail-to-tail dimer 53 when Pdfacac) and (BuO)jP are used as the catalyst. The head-to-head dimer 54 is obtained with Pd(acac)2, BF,. and tricyclohexylphosphine(54]. 

Normally, the oxidative addition of an aryl chloride to Pd(0) is reluctant to take place. But such a process is greatly accelerated in the presence of sterically hindered, electron-rich phosphine ligands [e.g., P(/-Bu)3 or tricyclohexylphosphine]. In late 1990s, Reetz [76] and Fu [77] successfully conducted intermolecular Heck reactions using arylchlorides as substrates, as exemplified by the conversion of p-chloroanisole to adduct 77 [77], The applications of this discovery will surely be reflected on future Heck reactions of non-activated heteroaryl chlorides. 

The bis(tricyclohexylphosphine) complexes are 14-electron species and are highly reactive. They are easily oxidized by air,48 and even decompose when stored in an inert atmosphere. However, they will readily coordinate an additional small ligand. Many of these small ligands bind through carbon and are, therefore, outside the scope of this review. Both dinitrogen48,49 and sulfur dioxide form adducts (equations 9 and 10).so... 

Chloroaryls, which are electronically deactivated and thus resistant to enter to the oxidative addition, were coupled with phenyltributyltin (PhSnBus) by using tricyclohexylphosphine (Pcys) adducts of palladium in K3PO4 and 1,4-dioxane to yield the corresponding biaryls in good yield. ... 

When anhyd HCl is bubbled through trans-IrCl(CO)(PPh3)2 in ether, the product HIr(Cl)2(CO)(PPh3)2 is formed rapidly and quantitatively. In nonpolar solvents or in the solid state the cis isomer is obtained. In polar solvents mixtures of cis and trans adducts formT When the phosphine is tri-o-tolylphosphine, HX addition to trans-IrCl(CO)(PR3)2 is slow because the apical sites are blocked. When the sterically bulky but strongly basic tricyclohexylphosphine is incorporated into trans-IrCl(CO)(PR3)2, the HCl adduct is formed easily. Moreover, when the phosphine of the complex is PMCjCo-MeOCjHp, interaction of the methoxy oxygen with the Ir center increases its nucleophilicity and so facilitates oxidative addition. ... 

Tricyclohexylphosphines with remote sulfate groups (Figure 2.8) have been prepared by alternative pathways by intermediary protection of the trivalent phosphorus as BHj adduct [97]. 

The genesis of the Morita-Baylis-Hillman (MBH) reaction began rather inauspiciously. In 1968, Morita described the reaction between an aldehyde and acrolein nitrile as well as methyl acrylate in the presence of tricyclohexylphosphine to afford 2-(l-hydroxyethyl) acrylonitrile and 2-(l-hydroxyethyl) methyl acrylate adducts in low yields (< 20%). An example is shown below using methyl acrylate 4 and acetaldehyde 5. 

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