Nickel-Containing Cyclic Amide Complexes

All reactions and manipulations should be carried out under an atmosphere of dry nitrogen or argon using Schlenk tube techniques.3 Solvents are dried over Na wire, distilled under an atmosphere of nitrogen, and stored under an atmosphere of nitrogen. 

5-cyclooctadiene)nickel, Ni(cod)2, is prepared according to the literature,4 as is tricyclohexylphosphine, tcyp.5 The latter must be recrystallized from rigorously dried diethyl ether. Methacrylamide (2-methyl-2-pro-penamide) was purchased from Tokyo Kasei (99% purity, authors) or from Ega Chemie (98-99% purity, checkers). Allylcyanide (3-butenenitrile) was purchased from Tokoyo Kasei (99% purity, authors) or from Merck-Schuchardt (98% purity, checkers). 

3-Butenamide is prepared according to the literature.6 A mixture of 3-butenenitrile (10mL), H20 (2.2 mL), and cone H2S04 (6.9 mL) is prepared at 

[2-METH YLPROPANAMID ATO(2—)-C3, A1 (IRICYCLOHEX YL-PHOSPHINE)NICKEL(II), SjiCH2CH(CH3)CONH(tcyp) 

Ni(cod)2 + CH2=C(CH3)CONH2 + tcyp — NiCH 2CH(CH3 )CON H(tcyp) + 2cod tcyp = tricyclohexylphosphine 

A tetrahydrofuran (THE) (20 mL) solution of a mixture of 1.7 g (6.2 mmol) of bis(l, 5-cyclooctadiene)nickel, Ni(cod)2, 1.7 g (6.2mmol) of tricyclohexylphosphine, and 1.1 g (13 mmol) of 2-methyl-2-propenamide (methacrylamide) is stirred for 6 h at room temperature in a nitrogen-filled 50-mL Schlenk tube equipped with a magnetic stirring bar. A greenish-yellow precipitate results. The reaction mixture is cooled to — 30 °C, and after 2 h the solvent containing 

[BUTANAMIDATO(2 - )-C, A] (TRICYCLOHEX YL-PHOSPHINE)NICKEL(n), l iCHjCHjCHjCOI H(tcyp) 

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Yamamoto T, Igarashi K, Komiya S, Yamamoto A (1980) Preparation and properties of phosphine complexes of nickel-containing cyclic amides and esters [(PR3) NiCH2CH(R ) COZ (Z = NR, O)]. J Am Chem Soc 102 7448-7456... 

Y amamoto T, Sano K, Osakada K, et al. Comparative smdies on reactions of a, fl- and P, y-imsaturated amides and acids with nickel(0), palladium(O), and platinum(0) complexes. Preparation of new five- and six-membered nickel- and palladium-containing cyclic amide and ester complexes. Organometallics. 1990 9 2396-2403. 

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