ca01 only detailed ToC 1..24

66 Science of Synthesis 1.1 Organometallic Complexes of Nickel
The slurry was then warmed to rt and stirred for 30 min. Additional THF (1 mL) was added
to facilitate stirring. The alkene (288 mg, 0.98 mmol) and [Ni(acac) 2](1; 18mg, 0.07 mmol)
were added sequentially as solids, and the resulting dark soln was heated immediately to
49–50 8C for 2–3 h. The reaction was monitored by HPLC and upon completion was
quenched with aq 1 M NH 4Cl. The resulting mixture was partitioned with EtOAc and the
organic layer was dried (Na 2SO 4) and concentrated under reduced pressure. The residue
was chromatographed to afford 73; yield: 348mg (93%).
1-[(1R*,2R*,3R*)-2-Acetyl-3-phenylcyclohexyl]acetone [(1R*,2R*,3R*)-75]: [131]
A1.59Mt-BuLi soln in pentane (1.7 mL, 2.7 mmol) was added dropwise to a soln of PhI
(0.273 g, 0.150 mL, 1.34 mmol) in THF (6 mL) at –788C. After stirring for 30 min at –788C
the yellow mixture was allowed to warm to 08C, and 1.0 M ZnCl 2 in Et 2O (0.90 mL,
0.90 mmol) was added dropwise by syringe. After 1 h, the resulting mixture and a soln of
[Ni(cod) 2](2; 5 mg, 0.018mmol) in THF (2 mL) were simultaneously transferred by cannula
to a soln of 74 (72 mg, 0.40 mmol) in THF (1 mL) at 08C. After stirring at 0 8C for 2 h the
brown mixture was quenched with sat. NaHCO 3 (25 mL), extracted with EtOAc
(3 ” 25 mL), dried (Na 2SO 4), filtered, and concentrated. Flash chromatography (silica gel,
hexanes/EtOAc 5:1) afforded, in order of elution, (1S*,2R*,3R*)-75 as a pale yellow oil and
(1R*,2R*,3R*)-75 as a white solid; both were homogeneous as judged by TLC analysis;
yields: (1S*,2R*,3R*)-75, 12 mg (12%); (1R*,2R*,3R*)-75, 60 mg (58%).
1.1.4.2.3 Variation3:
Organozirconiums
The conjugate addition of organozirconium reagents in the presence of catalytic amounts
of bis(acetylacetonato)nickel(II) (1) has received a modest level of attention (Scheme
61). [139–142] The alkenylzirconium 76 may be generated in situ by treatment of alkynes
with chloro(hydrido)zirconocene. It has perhaps received less attention than might be expected
owing to the popularity of the copper-catalyzed conjugate addition of organozirconiums.
[143]
Scheme 61 Conjugate Addition of Alkenylzirconiums [140–143]
ZrCp2Cl(H)
H Cp2ClZr H
H
76
O
Ni(acac)2 1
3-[(E)-3,3-Dimethylbut-1-enyl]cyclohexanone (77): [139]
Complex 76 (1.924 g, 5.67 mmol) and cyclohex-2-enone (0.623 g, 6.48mmol) were dissolved
in THF (30 mL) and cooled to 08C. [Ni(acac) 2](1; 0.151 g, 0.59 mmol) was added and
the mixture was stirred at 0 8C for 6.5 h. The mixture was quenched with NH 4Cl and extracted
with Et 2O. Compound 77 was isolated by distillation of the Et 2O solvent, followed
by preparative liquid chromatography of the resulting oil. Distillation of solvent from the
fraction containing the product gave 77; yield: 0.744 g (73%).
73%
O
77