CMDITR Review of Undergraduate Research - Pluto - University of ...

Suzuki Coupling (4)
The phenyl-pyridine structure was
synthesized by coupling 3 with 3-
formalphenylboronic acid via the Suzuki
coupling giving compound 4 in 45% yield. The
reaction was carried out in dioxane, oxygen and
light free. The solvents, THF and Aqueous
K 2 CO 3 were sparged for an hour and the reaction
apparatus was covered in aluminum foil. To a
solution of 3 (1g, .0054mol), 3-
formalphenylboronic acid (.81g, 0.0054mol) and
Pd(0)(PPh3)4 catalyst (0.03% mol wt), aqueous
K 2 CO 3 (1.2g, 0.0087mol) was added dropwise at
100ºC. The reaction was stirred at temperature
for 48 hours under nitrogen. The dioxane was
removed under reduced pressure and the product
was extracted with methylene chloride. The
methylene chloride layer was dried over sodium
sulfate before being removed under reduced
vacuum yielding crude product. The crude
product was purified on a silica gel column ran
with 10% ethyl acetate in methylene chloride.
Product was the second band resulting in white
solid. Mass Spec; fragments at 212.0g/mol,
198.0g/mol, and 184.0g/mol.
Horner Emmons (5)
The aldehyde of 4 was reacted with the
donor phosphate giving compound 5 in 25%
yield. To a solution of 4 (0.7g, 0.0035mol) and
N-dibutylaniline phosphinate (2.67g, 0.0078mol)
in dry THF, potassium butoxide (14mL,
0.014mol) was added dropwise at 0ºC resulting
in an immediate color change to dark green and
highly florescent. The reaction stirred at room
temperature for 18 hours. The THF was removed
under reduced pressure and the resulting solid
was taken in methylene chloride and given
subsequent water washes. The methylene
chloride layer was dried over sodium sulfate and
removed under reduced pressure resulting in
crude product. The crude product was purified
on a silica gel column ran with a liquid phase of
20% ethyl acetate in methylene chloride. The
product was the first red band. The red color was
due to the ligand complexing with the silica. The
poor yield was due to the decomposition of
starting material by potassium butoxide, future
reactions will be ran with milder conditions.
Mass Spec, dominate peaks at: 614.4g/mol,
399.2g/mol, and 234.2g/mol.
Iridium Complexing
56 CMDITR Review of Undergraduate Research Vol. 1 No. 1 Summer 2004