Chemistry Reference
In-Depth Information
1,4-diaminoanthraquinone [51]; N,N
0
-bis(3-aminopropyl)piperazine; 3,3
0
- and 5,5
0
-(2,2
0
-
dipyridino) [51-55]. Synthesis of the internally functionalized monomers was
achieved via a three-component, single-pot reaction using glutaryl dichloride,
H
2
NC(CH
2
CH
2
CO
2
CMe
3
)
3
, and the bis-diamine to give the homologated amino-
triester, H
2
NRNHCO(CH
2
)
4
CONHC(CH
2
CH
2
CO
2
CMe
3
)
3
, where R
an appropri-
ate diamine possessing the desired host-guest recognition component.
¼
3.2.4 Pentaerythritol-Based
Although 4-(hydroxymethyl)-2,6,7-trioxabicyclo[2.2.2]acetate (R
¼
H) has been
constructed (
50%) by treatment of pentaerythritol with HC(OEt)
3
[56,57], the
orthoacetate was shown to enhance the monomer's versatility [58]. Treatment of
HOCH
2
C(CH
2
O)
3
CH with CH
2
¼
CHCO
2
CH
2
C(CH
2
O)
3
CH;
whereas, pentaerythritol with HBr in AcOH gave (70%) BrCH
2
C(CH
2
OH)
3
, which
was transformed (60%) to BrCH
2
C(CH
2
O)
3
CH [59]. Treatment of C(CH
2
OH)
4
with
MeC(OMe)
3
gave (85%) 1-methyl-4-(hydroxymethyl)-2,6,7-trioxabicyclo[2.2.2]-
acetate (R
CHCOCl gave CH
2
¼
Me) [60], HOCH
2
C(CH
2
O)
3
CMe, or (80%) HOCH
2
C(CH
2
O)
3
CEt
when EtC(OEt)
3
was used [61]. The free hydroxy permits selective functionali-
zation at one arm, then deprotection of the orthoester and simple conversion to a
series of useful reagents: ROCH
2
C(CH
2
OSCN)
3
,C
6
H
5
CH
2
OCH
2
C(CH
2
SH)
3
, and
CH
2
¼
¼
CHCH
2
OCH
2
C(CH
2
SH)
3
[62]. Treatment of HOCH
2
C(CH
2
O)
3
CMe with
allyl bromide,
followed by hydrolysis, gave CH
2
¼
CHCH
2
OCH
2
C(CH
2
OH)
3
,
which with SOCl
2
(pyr) generated CH
2
¼
CHCH
2
OCH
2
C(CH
2
Cl)
3
, and with LiPPh
2
afforded CH
2
¼
CHCH
2
OCH
2
C(CH
2
PPh
2
)
3
[63]. Treatment of HOCH
2
C(CH
2
Cl)
3
,
prepared directly from pentaerythritol with 3.3 equiv. of SOCl
2
,wth
Me
3
SiC
CCH
2
Br (KOH) gave HC
CCH
2
OCH
2
C(CH
2
Cl)
3
, which was converted
to HC
CCH
2
OCH
2
C(CH
2
PPh
2
)
3
[63]. Treatment of C(CH
2
OCOCH
2
CH
2
SH)
4
with ethyl acrylate underwent a thio-Michael addition reaction in the presence
of HNEt
2
to give the 1
3 monomer, EtO
2
CCH
2
CH
2
SCH
2
CH
2
CO
2
CH
2
C(CH
2
-
OCOCH
2
CH
2
SH)
3
, along with other addition products [64].
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