Abstract
Several aromatic aldehydes are transported by a fluorous amine
from one organic phase through a fluorous phase to another organic
phase. The derived imines react with phenylhydrazine to immobilize
the transported product as a hydrazone and release the amine for
reuse. In this way, catalytic transport is accomplished for the
first time.
Key words
triphasic reaction - transport - fluorous chemistry - U-tube - fluorous amine
References and Notes 1 DPC holds an equity interest in Fluorous
Technologies, Inc.
2a Gladysz JA.
Emnet C. In The Handbook of Fluorous Chemistry
Gladysz JA.
Curran DP.
Horvath IT.
Wiley-VCH;
Weinheim:
2004.
p.11-23
2b Ryu I.
Matsubara H.
Emnet C.
Gladysz JA.
Takeuchi S.
Nakamura Y.
Curran DP. In Green Reaction Media in Organic Synthesis
Blackwell;
Ames
IO:
2005.
p.59-124
2c Iskra J.
Lett.
Org. Chem.
2006,
3:
170-175
2d Ryu I.
Matsubara H.
Nakamura H.
Curran DP.
Chem. Rec.
2008,
351
3 Nakamura H.
Linclau B.
Curran DP.
J.
Am. Chem. Soc.
2001,
123:
10119
4 Luo ZY.
Swaleh SM.
Theil F.
Curran DP.
Org. Lett.
2002,
4:
2585
5 The controls were conducted similarly
to the transport experiments. Aldehydes were vortexed with 1 equiv
of amine or hydrazine for 1 h in MeCN. Formation of the imine or
hydrazone was quantitative as assayed by GC. These samples then
served as standards for the transport experiments.
6 Gladysz JA.
Emnet C.
Rábai J. In The Handbook of Fluorous Chemistry
Gladysz JA.
Curran DP.
Horvath IT.
Wiley-VCH;
Weinheim:
2004.
p.56-100
7 The Kp ([FC-72]/[CH3 CN])
of 3 and 5 were
measured by direct partitioning as 2.3 and 0.8, respectively.
8 About 5-10% of the
volume of the FC-72 phase was lost in each cycle, presumably due
to evaporation. This was made up by adding additional FC-72 at the
beginning of each new cycle to return the volume to 7 mL.
9 We also considered that transport of
the aldehyde might occur by accidental transfer of some of the organic
source phase to the receiving phase during the cycles. But we did not
observe back transfer of the hydrazine or hydrazone, so this seems
unlikely.
