Side chain effect on the double helix formation of ethynylhelicene oligomers

ARTICLE

pubs.acs.org/joc

Side Chain Effect on the Double Helix Formation

of Ethynylhelicene Oligomers

Nozomi Saito, Ryo Terakawa, Masanori Shigeno, Ryo Amemiya, and Masahiko Yamaguchi*^,†

Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan

^†WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan

S Supporting Information

b

ABSTRACT: Three series of ethynylhelicene oligomers with dif-

ferent side chains were synthesized: (P)-bD-n (n = 2ꢀ6) with

branched alkyloxycarbonyl side chains; (P)-S-n (n = 2ꢀ7) with

decylsulfanyl side chains; and (P)-DF-n (n = 4, 6, 8, 10) with alter-

nating decyloxycarbonyl and perﬂuorooctyl side chains. The

double helix formation of these side chain derivatives was

compared to that of (P)-D-n with decyloxycarbonyl side chains.

CD, UVꢀvis, and vapor pressure osmometry (VPO) studies

showed that (P)-bD-n formed double helices as well as (P)-D-n.

CD studies in triﬂuoromethylbenzene at diﬀerent temperatures

and concentrations indicated that the stability of the aggregate of (P)-bD-6 was similar to that of (P)-D-6. Bulkiness of side chains

had little eﬀect on aggregation, which indicated that πꢀπ interactions of the aromatic moiety were essential for double helix

formation. (P)-S-n were random coils in all solvents examined except in triﬂuoromethylbenzene. Whereas (P)-D-7 formed a double

helix at 1 ꢁ 10^ꢀ3M in toluene, (P)-S-7 was a random coil. This result indicated that the double helix forming ability of (P)-S-n was

substantially lower than that of (P)-D-n. Based on the previous observation that (P)-F-n formed a more stable double helix than (P)-

D-n, the order of stability may be summarized as follows: (P)-F-n > (P)-D-n and (P)-bD-n > (P)-S-n. The lower stability of (P)-S-n

compared to that of (P)-F-n was ascribed to the softness and/or the electron-rich nature at the m-phenylene moiety. (P)-DF-n did

not form a stable double helix. It was speculated that a regular alternating arrangement of soft/hard or electron-rich/deﬁcient

moieties is important for stable double helix formation. Side chains of ethynylhelicene oligomers can play signiﬁcant roles in

determining the stability of double helices.

’ INTRODUCTION

oligomers depends on the identity of the side chain.^4c,32

A

heptamer with seven decyloxy side chains in CDCl₃or C₆D₆

has a dimerization constant 3 orders of magnitude larger than

that with three decyloxy side chains or one lacking a side chain. It

was proposed that long side chains are involved in van der Waals

interactions between strands. In CDCl₃, the dimerization con-

stants of a pyridine-dicarboxamide heptamer³³and a nonamer³⁴

with benzyloxy side chains on the pyridine rings are much higher

than those with decyloxy or methoxy side chains. This result has

been ascribed to the interstrand face-to-face and edge-to-face

interactions between the benzyl groups. Similar dimerization

constants, which were higher than those of unsubstituted oligo-

mers, were obtained for the decyloxy and methoxy derivatives of

the same oligomers.³³These results were ascribed to the reduced

unfavorable dipolar interactions by alkyloxy-substituted oligo-

mers. These examples show that side chains aﬀect the stability of

helix formation by aromatic oligomers. However, systematic

understanding of the eﬀects of side chains remains insuﬃcient,

and thus further study is required.

Synthetic oligomeric compounds that can form helical

structures,¹such as single helices,^2ꢀ17double helices,^18ꢀ26and

multiple helices,^27ꢀ29have recently attracted attention. In gen-

eral, these organic compounds possess an array of aromatic

moieties with long alkyl side chains, which are introduced to

improve their solubility in organic solvents. In some cases,

however, side chains aﬀect helix formation.

In the case of a single helix, whereas the m-phenylene ethynylene

oligomer with triethyleneglycoxycarbonyl [CO₂CH₂(CH₂CH₂O)₃-

CH₃] side chains forms a single helix in acetonitrile, which is a polar

solvent, the oligomers with triethyleneglycoxy [OCH₂(CH₂CH₂O)₃-

CH₃] side chains or triethyleneglycoxymethyl [CH₂OCH₂-

(CH₂CH₂O)₃CH₃] side chains require solvents of higher

polarity, such as a combination of acetonitrile and water, for

helix formation.³⁰A triblock oligomer with both triethylenegly-

coxycarbonyl and triethyleneglycoxymethyl side chains shows

intermediate aggregation. It has been discussed that electron-

withdrawing groups strengthen π-stacking.³¹

The side chain eﬀect on the double helix formation of aromatic

oligoamides has also been discussed. The dimerization constant

for the double helix formation of pyridine-dicarboxamide

Received: January 12, 2011

Published: May 04, 2011

r

2011 American Chemical Society

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Figure 1. Side chain eﬀect.

Scheme 1

Previously we reported double helix formation by optically

active ethynylhelicene oligomers, in which (P)-5,8-diethynyl-

1,12-dimethylbenzo[c]phenanthrene moieties were connected

by m-phenylene spacers possessing decyloxycarbonyl side chains

(Figure 1).^35,36The circular dichroism (CD) spectrum obtained

within 5 min after the dissolution of the heptamer (P)-D-7 in

chloroform at 5 ꢁ 10^ꢀ6M was markedly diﬀerent from the

spectra of oligomers from the dimer to the hexamer and exhibited

an extremely large Cotton eﬀect between 300 and 400 nm.

Hypochromic shifts were also observed in the UVꢀvis spectra.

Vapor pressure osmometry (VPO) revealed a dimeric structure

of (P)-D-7 when it showed the enhanced Cotton eﬀect. The

proton NMR of (P)-D-7 in chloroform at room temperature

provided broad signals of aromatic protons shifted upﬁeld, which

indicated the formation of π-stacked structures. The results

indicated the formation of a double helix by (P)-D-7. The double

helix unfolded to random coils by heating, and investigations of

the unfolding rate of (P)-D-7 revealed that the rate constant k

was highly dependent on the type of aromatic solvents used. The

k values diﬀered by 7 orders of magnitude between iodobenzene

and triﬂuoromethylbenzene, and log k exhibited a good correla-

tion with the absolute hardness η:³⁷higher unfolding rates were

observed in soft arenes and lower rates in hard arenes.^36aThe

results suggested the involvement of πꢀπ interactions in double

helix formation and a notable relationship between the πꢀπ

interactions and the HSAB principle: the πꢀπ interaction is a

soft/soft interaction between arenes.

Later, we synthesized oligomers with perﬂuorooctyl side

chains at the m-phenelene moiety (Figure 1).³⁸Pentamer (P)-

F-5 formed a double helix in hard solvents such as triﬂuoro-

methylbenzene, m-diﬂuorobenzene, and ﬂuorobenzene as indi-

cated by CD and VPO, and it was noted that (P)-F-5 formed a

more stable double helix than (P)-D-5. The CD spectra of (P)-F-

5 in triﬂuoromethylbenzene provided a mirror-image CD spec-

trum compared to that of (P)-D-5, which meant that their screw

senses are inverted with respect to each other. (P)-F-5 formed a

heteroaggregate with (M)-D-5 but not with (P)-D-5. The

heteroaggregate also provided a CD spectrum similar to those

of double helices of (P)-F-5 and (M)-D-5. Signiﬁcant chiral

recognition in the aggregate formation can be explained by the

formation of chiral ordered three-dimensional structures of

double helices. In addition, the results indicated the crucial role

of side chains in determining the structure and stability of double

helices, which led us to further investigate side chain eﬀects.

In this study, we synthesized a new series of ethynylhelicene

oligomers with diﬀerent side chains and examined their double

helix formation (Figure 1). (P)-bD-n (n = 2ꢀ6) with 4-methyl-

2-(2-methylpropyl)-1-pentyloxy carbonyl side chains were

synthesized to determine the eﬀect of bulkiness at the side chain

moiety. (P)-S-n (n = 2ꢀ7) with decylsulfanyl side chains were

synthesized to investigate the eﬀect of soft and electron-donating

side chains on m-phenylene moieties. (P)-DF-n (n = 4, 6, 8, 10)

with alternating decyloxycarbonyl and perﬂuorooctyl side chains

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Scheme 2

Scheme 3

were synthesized to determine the eﬀects of alternating

arrangements.

directional method.^39a(P)-bD-n (n = 2ꢀ6) were synthe

sized starting from 4-methyl-2-(2-methylpropyl)pentyl-3,5-bis-

(trifluoromethanesulfonyloxy) benzoate 5, which was obtained

from diethyl-2,2-bis(2-methylpropyl)propanedionate 1 in four

steps (Scheme 1). The coupling of monosilylated ethynylheli-

cene (P)-6 and 4 equiv of 5 gave the building block (P)-bD-1

(Scheme 2). The dimer (P)-bD-2 was synthesized from 5 and

(P)-6 in 95% yield. The coupling of diethynylhelicene (P)-7 and

(P)-bD-1 yielded the trimer (P)-bD-3 in 91% yield, and sub-

sequent deprotection and Sonogashira coupling converted (P)-

bD-3 to (P)-bD-5 in 92% yield. The tetramer (P)-bD-4 (n = 4)

and the hexamer (P)-bD-6 (n = 6) were synthesized starting from

the deprotected dimer (P)-bD-2H in 92% and 94% yield,

respectively.

The synthesis of (P)-S-n (n = 2ꢀ7) employed 5-decylsulfanyl-

1,3-bis(triﬂuoromethanesulfonyloxy)-benzene 11, which was

obtained from 3,5-dimethoxybenzenethiol 8 in three steps

(Scheme 3). Coupling with 11 and (P)-6 gave (P)-S-1 in 94%

yield (Scheme 4). The oligomers with odd numbers of helicenes,

(P)-S-3, (P)-S-5, and (P)-S-7, were obtained starting from (P)-7

by coupling with 2 equiv of (P)-S-1 in 83%, 81%, and 55% yield,

respectively. The dimer (P)-S-2 was synthesized from 11 and 2

equiv of (P)-6 in 89% yield. The subsequent deprotection and

Sonogashira coupling converted (P)-S-2 to (P)-S-4 in 81% yield

and then to (P)-S-6 in 65% yield. Because of poor solubility,

For clariﬁcation, the names of oligomers are represented as

follows. Decyloxycarbonyl compounds, perﬂuorooctyl com-

pounds, and 4-methyl-2-(2-methylpropyl)-1-pentyloxycarbonyl

compounds are denoted “D”, “F”, and “bD”, respectively. Com-

pounds with decylsulfanyl side chains are denoted “S”, and

compounds with alternating decyloxycarbonyl and perﬂuorooc-

tyl side chains are denoted “DF”. The bold-faced number

represents the number of helicenes in an oligomer. Desilylated

synthetic intermediates are denoted “H”, for example, (P)-D-2H.

(P)-bD-n showed double helix formation behavior similar to

that of (P)-D-n, which indicated a small eﬀect due to side chain

bulkiness. The aggregate-forming ability of (P)-S-n was substan-

tially lower than those of (P)-F-n and (P)-D-n. The results were

explained by the importance of hardness and/or electron-deﬁcient

nature of the m-phenylene moiety to form stable aggregates. (P)-

DF-n did not form stable double helices. It was speculated that the

arrangement of regular alternating soft/hard and/or electron-

deﬁcient/rich arrays is important for stable double helix formation.

’ RESULTS AND DISCUSSION

Synthesis. Ethynylhelicene oligomers were synthesized by

repetitive deprotection and Sonogashira coupling in a two-

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Scheme 4

Scheme 5

oligomers longer than (P)-S-7 were not obtained in reasonable

yields.

deprotection, (P)-DF-4 was converted to the hexamer (P)-DF-

6 in 80% yield by coupling with (P)-F-1. Analogously, the

octamer (P)-DF-8 and the decamer (P)-DF-10 were obtained

in 79% and 40% yield, respectively.

Aggregation of (P)-D-n. Before conducting the study of the

newly synthesized oligomers with different side chains, the

(P)-DF-n (n = 4, 6, 8, 10) were synthesized using (P)-D-1 with

decyloxycarbonyl side chains^39aand (P)-F-1 with perﬂuorooctyl

side chains (Scheme 5).³⁸The tetramer (P)-DF-4 was obtained

in 89% yield by coupling (P)-F-2H³⁸and (P)-D-1. After

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Figure 3. CD spectra (5 ꢁ 10^ꢀ4M) of (P)-D-8 in chloroform.

Solutions were heated at 60 °C and then cooled at 5 °C. The spectra

did not change between 3 and 4 h at 25 °C. CD spectra of (P)-D-8 (5 ꢁ

10^ꢀ6M, 25 °C) in chloroform are also shown.

365 nm (Figure 4a). The UVꢀvis spectra of the higher oligomers

of (P)-D-n (n = 6ꢀ8) showed a decrease in absorption

and hypochromic shifts. The results of CD and UVꢀvis studies

indicated stable double helix formation of (P)-D-6, (P)-D-7, and

(P)-D-8 in triﬂuoromethylbenzene at equilibrium.

At a higher concentration (1 ꢁ 10^ꢀ3M) in triﬂuoromethyl-

benzene, bimolecular aggregate formation was promoted, and

even pentamer (P)-D-5 exhibited the CD spectra of a double

helix at 25 °C (Figure 5). At 10 °C, (P)-D-4 also showed the

enhanced Cotton eﬀect of a double helix, while (P)-D-2 and (P)-

D-3 did not (Figure 5). The dimeric aggregation of (P)-D-4 at

concentrations higher than 1 ꢁ 10^ꢀ3M was conﬁrmed by VPO

(triﬂuoromethylbenzene, 35 °C) (Figure S1).⁴⁰

We previously reported that a cyclic ethynylhelicene oligomer

containing three ethynylhelicenes and three m-phenylenes

strongly forms a dimeric aggregate.³⁹Taking account of this

observation and the results obtained here, we assumed that one

turn of the double helix contained three helicenes and three m-

phenylenes, and at least four helicenes were required to form a

helical conformation (Figure 6) in which one terminal helicene

lay on the other.

Figure 2. CD (top) and UVꢀvis (bottom) spectra (5 ꢁ 10^ꢀ6M,

25 °C) of (P)-D-n (n = 2ꢀ8) in chloroform. Solutions were heated at

60 °C and then cooled to 25 °C. The spectra did not change between

15 and 30 min at 25 °C.

homoaggregation of (P)-D-n (n = 2ꢀ8) was re-examined. CD

and UVꢀvis analyses were conducted in chloroform and tri-

fluoromethylbenzene, which are relatively weak and strong helix-

forming solvents, respectively.^37a,bIn the previous work,^36a

spectroscopic studies were conducted within 5 min after dissolu-

tion at a concentration of 5 ꢁ 10^ꢀ6M to examine the unfolding

rate. In this study, equilibrated states were examined by heating

solutions at higher temperatures to unfold the double helix. Then

the solutions were cooled to 25 °C, and the spectra after reaching

a steady state were obtained.

In chloroform (5 ꢁ 10^ꢀ6M, 25 °C), the CD and UVꢀvis

spectra of (P)-D-2, (P)-D-3, (P)-D-4, (P)-D-5, (P)-D-6, and

(P)-D-7 showed a monotonic increase in accordance with the

number of helicenes (Figure 2). All spectra obtained after 15 min

at 25 °C were unchanged after 30 min and were conﬁrmed to be

in an equilibrated state. The spectra were similar to those

obtained in the previous study,^36awhich indicated random coil

states for these compounds at equilibrium. (P)-D-8 showed a

slightly enhanced Cotton eﬀect at 365 nm, and the spectrum

was considered to reﬂect partial double helix formation. This

explanation was supported by the observation that (P)-D-8

provided a CD spectrum typical of a double helix at a higher

concentration of 5 ꢁ 10^ꢀ4M in chloroform at 5 °C (Figure 3).

In triﬂuoromethylbenzene (5 ꢁ 10^ꢀ6M, 25 °C), the CD

spectra of (P)-D-n obtained after 15 min were conﬁrmed to be

equilibrated except for (P)-D-6 and (P)-D-7, which reached

steady state after 90 min and 2 h, respectively. The absolute CD

values |Δε| at 335 and 385 nm for (P)-D-2, (P)-D-3, and (P)-D-

4 showed a monotonic increase in accordance with the number

of helicenes. (P)-D-5 showed a slightly diﬀerent shape

(Figure 4b), and (P)-D-6, (P)-D-7, and (P)-D-8 showed quite

diﬀerent shapes; an increased |Δε| with maxima at 323 and

In m-diﬂuorobenzene and ﬂuorobenzene, which are less hard

aromatic solvents than triﬂuoromethylbenzene, (P)-D-8 showed

the CD spectra of a double helix (Figure 7). In soft solvents such

as toluene, chlorobenzene, bromobenzene, and iodobenzene,

(P)-D-8 provided the CD spectra of random coils (Figure S2). In

the following discussions, the stability of oligomers with diﬀerent

side chains is compared with that of the double helix formation of

(P)-D-n at equilibrium in these solvents.

Aggregation of (P)-bD-n. The CD and UVꢀvis spectra of

(P)-bD-n (n = 2ꢀ6) in chloroform (5 ꢁ 10^ꢀ6M, 25 °C) showed

a monotonic increase in accordance with the number of helicenes

and were similar to those of (P)-D-n in the random coil state

(Figure 8a).

In triﬂuoromethylbenzene, the CD spectra of (P)-bD-6

reached equilibrium after 2 h and showed enhanced Cotton

eﬀects. Hypochromic shifts were observed in UVꢀvis spectra,

which indicated double helix formation analogous to that of (P)-

D-6 (Figure 8b). A dimeric aggregate of (P)-bD-6 was conﬁrmed

by VPO (triﬂuoromethylbenzene, 35 °C) (Figure 9).

In m-diﬂuorobenzene and ﬂuorobenzene, which are less hard

aromatic solvents than triﬂuoromethylbenzene, (P)-bD-6

showed CD spectra of random coils (Figure S3). In soft solvents

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Figure 5. CD spectra (10 °C, 1 ꢁ 10^ꢀ3M) of (P)-D-n (n = 2ꢀ4) and

spectra (25 °C, 1 ꢁ 10^ꢀ3M) of (P)-D-n (n = 5ꢀ8) in triﬂuoromethyl-

benzene. Solutions were heated at 60 °C and then cooled to 10 or 25 °C.

The spectra did not change between 30 min and 1 h at each temperature.

Figure 6. Proposed model of the double helix structure. Two com-

pounds that form a double helix are shown in diﬀerent colors.

Figure 4. (a) CD (top) and UVꢀvis (bottom) spectra (5 ꢁ 10^ꢀ6M,

25 °C) of (P)-D-n (n = 2ꢀ8) in triﬂuoromethylbenzene. Solutions were

heated at 80 °C and then cooled to 25 °C. The spectra did not change

between 15 and 30 min at 25 °C. As an exception to this, (P)-D-6 and

(P)-D-7 required 90 min and 2 h to reach the steady state at 25 °C,

respectively. (b) Magniﬁed CD spectra (5 ꢁ 10^ꢀ6M, 25 °C) of (P)-D-n

(n = 2ꢀ5) in triﬂuoromethylbenzene.

such as toluene, chlorobenzene, bromobenzene, and iodoben-

zene, (P)-bD-6 showed CD spectra of random coils (Figure S4).

The solvent eﬀect on the aggregation of (P)-bD-6 showed a

tendency similar to that of (P)-D-6.

Figure 7. CD spectra (2.5 ꢁ 10^ꢀ6M, 25 °C) of (P)-D-8 in triﬂuor-

omethybenzene, m-diﬂuorobenzene, and ﬂuorobenzene. Solutions were

heated at 80 °C and then cooled to 25 °C. The spectra did not change

between 15 and 30 min at 25 °C.

The stability of (P)-D-n and (P)-bD-n was compared on the

basis of CD spectra in triﬂuoromethylbenzene. In both series,

pentamers (P)-D-5 and (P)-bD-5 showed spectra of random

coils at 5 ꢁ 10^ꢀ6M, and hexamers (P)-D-6 and (P)-bD-6

showed spectra of double helices (Figure 4 and Figure 8b). The

aggregation was compared between (P)-D-6 and (P)-bD-6 at

diﬀerent temperatures and concentrations. A solution of (P)-D-6

in triﬂuoromethylbenzene (5 ꢁ 10^ꢀ6M) was ﬁrst heated at

60 °C, and the aggregate was unfolded to random coils and then

cooled to 25, 5, and ꢀ10 °C. The CD spectrum of (P)-D-6

showed double helix formation after 30 min at 25 °C, which did

not change by cooling to 5 or ꢀ10 °C (Figure 10a). The same

spectra were obtained at a higher concentration of 1 ꢁ 10^ꢀ3M at

5 °C (Figure 10a). Under the same conditions, (P)-bD-6 showed

CD spectra very similar to those of (P)-D-6 (Figure 10b). The

only exception was a slight decrease in the Cotton eﬀect at a

concentration of 5 ꢁ 10^ꢀ6M at 25 °C. The similar CD behavior

of (P)-D-6 and (P)-bD-6 indicated that both compounds formed

double helices with similar stabilities. The bulkiness at the side

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Figure 8. CD (top) and UVꢀvis (bottom) spectra (25 °C, 5 ꢁ 10^ꢀ6M) of (P)-bD-n (n = 2ꢀ6), in (a) chloroform and (b) triﬂuoromethylbenzene.

Solutions were heated at 60 °C in chloroform and at 80 °C in triﬂuoromethylbenzene and then cooled to 25 °C. The spectra did not change between 15

and 30 min at 25 °C. As an exception to this, (P)-D-6 required 2 h to reach the steady state at 25 °C.

Figure 9. Degree of aggregation of (P)-bD-6 obtained using VPO

(triﬂuoromethylbenzene, 35 °C) at several concentrations. Circles

represent an average of more than ﬁve measurements, and vertical lines

represent a range of results.

chains did not aﬀect the aggregation. The πꢀπ interactions of

the aromatic array of helicenes and m-phenylenes, therefore, are

crucial for double helix formation, and the interaction between

side chains was unimportant. This observation is consistent with

the double helix structure, in which the side chains occupy the

outside of the double helix (Figure 6).

Aggregation of (P)-S-n. The aggregation of (P)-S-n (n = 2ꢀ7)

was examined using the same method described for (P)-bD-n. In

chloroform (5 ꢁ 10^ꢀ6M, 25 °C), (P)-S-n (n = 2ꢀ7) showed CD

and UVꢀvis spectra of random coils with a monotonic increase as

Figure 10. CD spectra (triﬂuoromethylbenzene) of (a) (P)-D-6 and

the number of helicenes increased (Figure 11a).

(b) (P)-bD-6 at various temperatures and concentrations. Solutions at 5

In triﬂuoromethylbenzene (5 ꢁ 10^ꢀ6M, 25 °C), the CD and

UVꢀvis spectra of (P)-S-2, (P)-S-3, and (P)-S-4 showed a

monotonic enhancement of the Cotton eﬀect indicating random

coils. In contrast, the CD spectra of (P)-S-6 and (P)-S-7 showed

a slow change at 25 °C, and reached a steady state after 7 and

18 h, respectively. The spectra at equilibrium were diﬀerent from

those of random coils, and signiﬁcant hypochromic shifts were

ꢁ 10^ꢀ6M were heated at 60 °C and then cooled to 25, 5, and ꢀ10 °C.

Solutions at 1 ꢁ 10^ꢀ3M were heated at 60 °C and then cooled to 5 °C.

The spectra obtained under each set of conditions did not change after

30 min of each observation.

observed by UVꢀvis (Figure 11b). The results indicated aggre-

gate formation by these longer oligomers. VPO analysis,

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Figure 11. CD (top) and UVꢀvis (bottom) spectra (5 ꢁ 10^ꢀ6M, 25 °C) of (P)-S-n (n = 2ꢀ7) in (a) chloroform and (b) triﬂuoromethylbenzene.

Solutions were heated at 60 °C and then cooled to 25 °C. The spectra did not change between 15 and 30 min at 25 °C. As an exception to this, (P)-S-7

required 18 h to reach the steady state at 25 °C in triﬂuoromethylbenzene.

Figure 12. CD spectra (5 ꢁ 10^ꢀ6M, 25 °C) of (P)-S-7 in triﬂuor-

omethybenzene, m-diﬂuorobenzene, and ﬂuorobenzene. Solutions

were heated at 60 °C and then cooled to 25 °C. The spectra did

not change between 15 and 30 min at 25 °C. As an exception to this,

(P)-S-7 required 18 h to reach the steady state at 25 °C in

triﬂuoromethylbenzene.

however, could not be conducted because of their low solubility

in triﬂuoromethylbenzene.

In less hard aromatic solvents such as m-diﬂuorobenzene and

ﬂuorobenzene and soft solvents such as toluene, chlorobenzene,

bromobenzene, and iodobenzene, (P)-S-7 gave the CD spectra

(5 ꢁ 10^ꢀ6M, 25 °C) of random coils (Figures 12 and S5).

The aggregation of (P)-D-7 and (P)-S-7 in toluene was

compared. The solutions of (P)-D-7 and (P)-S-7 in toluene

Figure 13. CD spectra (toluene) of (a) (P)-D-7 and (b) (P)-S-7 at

were ﬁrst heated at 60 °C to unfold to random coils and then

cooled to 25 or 5 °C. Both (P)-D-7 and (P)-S-7 at 5 ꢁ 10^ꢀ6M

various temperatures and concentrations. Solutions were heated at

60 °C and then cooled to 25 or 5 °C. The spectra (5 ꢁ 10^ꢀ6M) did not

showed CD spectra of random coils at 25 °C (Figure 13). At 1 ꢁ

10^ꢀ3M, (P)-S-7 was a random coil at 5 °C, while (P)-D-7

showed the CD spectrum of a double helix (Figure 13). The

double helix of (P)-S-7 was less stable than that of (P)-D-7.

change between 15 and 30 min at 25 °C. The spectra (1 ꢁ 10^ꢀ3M) did

not change after 30 min of each observation at25 °C. The spectrum of

(P)-S-7 at 1 ꢁ 10^ꢀ3M was obtained at a wavelength region shorter

than 380 nm because of UVꢀvis absorption of (P)-S-7.

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Figure 14. CD (top) and UVꢀvis (bottom) spectra (5 ꢁ 10^ꢀ6M, 25 °C) of (P)-DF-4, (P)-DF-6, (P)-DF-8, and (P)-DF-10 (2.5 ꢁ 10^ꢀ6M for (P)-

DF-10) in (a) chloroform and (b) triﬂuoromethylbenzene. Solutions were heated at 60 °C in chloroform and at 80 °C in triﬂuoromethylbenzene and

then cooled to 25 °C. The spectra did not change between 15 and 30 min at 25 °C.

On the basis of our previous report³⁸that (P)-F-5 formed a

more stable double helix than (P)-D-5, the order of stability was

summarized as follows: (P)-F-n > (P)-D-n and (P)-bD-n > (P)-

S-n. This observation might be explained by the relation of

double helix stability to the hardness of the m-phenylene moiety:

(P)-F-n possessing the harder m-phenylene formed a more stable

double helix compared to that of (P)-S-n. The large π-electron

systems of helicene moieties should be soft in nature.^36aThen,

(P)-F-n has an alternating soft helicene moiety and hard m-

phenylene moiety, whereas in contrast (P)-S-n has soft arrays.

The regular alternating arrangement of soft and hard moieties

can form a rigid aggregate, which resulted in a stable double helix.

Another explanation for the stability order can be related to the

electronic nature of the m-phenylene moiety: electron-with-

drawing side chains stabilized the aggregation. The tendency

was experimentally supported by other groups^41,42and our

group^39din the case of arylene ethynylene macrocycles. We

speculated in this study that the regular alternating arrangement

of soft/hard and electron-rich/deﬁcient moieties provides a rigid

and stable double helix. Further systematic studies are required to

examine this speculation.

Aggregation of (P)-DF-n. The aggregation of (P)-DF-n

(n = 4, 6, 8, 10) was examined in chloroform (5 ꢁ 10^ꢀ6M,

25 °C). CD and UVꢀvis showed spectra of random coil states

with a monotonic increase with the number of helicenes

(Figure 14a). In chloroform at 45 °C, (P)-DF-4, (P)-DF-6,

and (P)-DF-8 were monomeric by VPO at concentrations

between 1 ꢁ 10^ꢀ3and 3 ꢁ 10^ꢀ3M (Figure S6). Thus, (P)-

DF-8 showed less tendency to form a double helix than (P)-D-8,

which formed a partial double helix at 5 ꢁ 10^ꢀ6M in chloroform.

In triﬂuoromethylbenzene (5 ꢁ 10^ꢀ6M, 5 °C), (P)-DF-4

showed a spectrum similar to that in chloroform (Figure 14b)

and was monomeric at the concentrations from 1 ꢁ 10^ꢀ3to

3 ꢁ 10^ꢀ3M by VPO (45 °C) (Figure S7a).⁴⁰Since (P)-D-4 in

the same solvent formed a double helix at concentrations

higher than 2 ꢁ 10^ꢀ3M at 35 °C (Figure S1), (P)-DF-4

showed less tendency to form a double helix than (P)-D-4.

CD and UVꢀvis spectra of (P)-DF-6 and (P)-DF-8, however,

were diﬀerent in triﬂuoromethylbenzene: the Cotton eﬀects

were considerably enhanced compared with those in chloro-

form (Figure 14b), and the absorption maxima in UVꢀvis

shifted to the longer-wavelength region, 338 to 350 nm for

(P)-DF-6 and 339 to 358 nm for (P)-DF-8. The observations

were diﬀerent from (P)-D-n, which showed a regular increase

in the Cotton eﬀect for (P)-D-4, (P)-D-5, (P)-D-6, (P)-D-7,

and (P)-D-8 under the helix-forming conditions in triﬂuor-

omethylbenzene (Figure 4a, Figure 5). VPO analysis indi-

cated that (P)-DF-6 and (P)-DF-8 formed aggregates higher

than dimers (Figure S7b,c). The CD spectrum of (P)-DF-10

in triﬂuoromethylbenzene (2.5 ꢁ 10^ꢀ6M, 25 °C) showed

features diﬀerent from those of (P)-DF-6 and (P)-DF-8 with

weak Cotton eﬀects. This may not be a random coil, because

a signiﬁcant shift of the UVꢀvis absorption maximum from

338 to 362 nm was observed, which was diﬀerent from the

UVꢀvis spectra in chloroform. The higher oligomers of

(P)-DF-n exhibited complex aggregation behavior in

triﬂuoromethylbenzene.

In m-diﬂuorobenzene, ﬂuorobenzene, toluene, chloroben-

zene, bromobenzene, and iodobenzene, (P)-DF-8 showed spec-

tra typical of random coils (Figures 15 and S8). The aggregation

of (P)-DF-8 was substantially less stable than that of (P)-D-8,

which formed a double helix in m-diﬂuorobenzene and ﬂuor-

obenzene as well as in triﬂuoromethylbenzene.

The double helices of (P)-DF-n were less stable than those of

(P)-F-n and (P)-D-n: (P)-F-n and (P)-D-n formed stable double

helices, and (P)-DF-n with alternating decyloxycarbonyl and

perﬂuorooctyl side chains did not exhibit properties intermediate

between (P)-F-n and (P)-D-n. (P)-DF-n possess a soft/electron-

rich helicene moiety, a relatively soft/electron-deﬁcient m-phe-

nylene moiety with decyloxycarbonyl side chains, and a hard/

electron-rich m-phenylene moiety with perﬂuorooctyl side

chains. The low stability of (P)-DF-n aggregates may be

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4-Methyl-2-(2-methylpropyl)-pentanoic Acid Ethyl Ester, 2. Under

an argon atmosphere, a mixture of diisobutylmalonic acid diethyl ester 1

(6.38 g, 23.4 mmol), lithium chloride (5.96 g, 0.141 mol), and water

(2.50 mL, 0.140 mmol) in dimethyl sulfoxide (68 mL) was heated under

reflux for 24 h. Then the mixture was cooled to room temperature, and

saturated aqueous ammonium chloride was added. After being stirred for

1 h, the organic materials were extracted with ethyl acetate three times.

The organic layer was washed with water and brine and dried over

magnesium sulfate. The solvent was evaporated under reduced pressure,

and separation by silica gel chromatography gave 2 as colorless oil (3.88

g, 19.4 mmol, 83%). LRMS (EI, 70 eV) m/z: 201 ([M þ H]^þ, 1.1%),

144 ([M ꢀ C₄H₈], 81%), 101 ([M ꢀ C₇H₁₅]^þ, 100%). HRMS m/z

calcd for C₁₂H₂₅O₂^þ: 201.1834. Found: 201.1855. IR (KBr) 2957, 2871,

1736, 1178 cm^ꢀ1. ¹H NMR (400 MHz, CDCl₃) δ 0.87 (6H, d, J = 6.4

Hz), 0.90 (6H, d, J = 6.4 Hz), 1.16ꢀ1.22 (2H, m), 1.25 (3H, t, J = 7.2

Hz), 1.49ꢀ1.51 (4H, m), 2.50 (1H, tt, J = 4.8 Hz), 4.13 (2H, q, J = 7.2

Hz). ¹³C NMR (100 MHz, CDCl₃) δ 14.3, 22.0, 23.0, 26.1, 41.7, 42.2,

59.9, 176.9.

Figure 15. CD spectra (2.5 ꢁ 10^ꢀ6M, 25 °C) of (P)-DF-8 in

triﬂuoromethybenzene, m-diﬂuorobenzene, and ﬂuorobenzene. Solu-

tions were heated at 80 °C and then cooled to 25 °C. The spectra did not

change between 15 and 30 min at 25 °C.

4-Methyl-2-(2-methylpropyl)-pentanol, 3. Under an argon atmo-

sphere, to a suspension of lithium alminium hydride (878 mg, 23.1

mmol) in tetrahydrofuran (67 mL) was slowly added 2 (3.86 g, 19.3

mmol) in tetrahydrofuran (10 mL) at ꢀ100 °C. Then the mixture was

warmed to 0 °C, and stirred for 2 h. At the temperature, sodium sulfate

decahydrate was added slowly until formation of hydrogen stopped.

Then, water (2ꢀ3 mL) was added, which was followed by excess sodium

sulfate. After being stirred at room temperature overnight, insoluble

materials were filtrated through Celite and washed with tetrahydrofuran

three times. The solvent was evaporated under reduced pressure, and

separation by silica gel chromatography gave 3 as colorless oil (2.95 g,

19.3 mmol, 97%). LRMS (EI, 70 eV) m/z: 140.15 ([M ꢀ H₂O], 9.9%),

83 ([C₅H₇O] ^þ, 65%), 71 ([C₄H₇O]^þ, 95%), 57 ([C₄H₉]^þ,_þ100%), 43

([C₃H₇]^þ, 72%). HRMS (FAB) m/z calcd for C₂₀H₄₅O₂([2M ꢀ

H]^þ): 317.3414. Found: 317.3432. IR (KBr) 3325 (br), 2954, 2917,

2871, 1468, 1048 cm^ꢀ1. ¹H NMR (400 MHz, CDCl₃) δ 0.88 (6H, d, J =

6.4 Hz), 0.89 (6H, d, J = 6.4 Hz), 1.07 (2H, ddd, J = 12.8, 6.4 Hz), 1.22

(2H, ddd, J = 12.8, 6.4 Hz), 1.55ꢀ1.71 (3H, m), 1.71ꢀ1.83 (1H, m, br),

3.51 (2H, d, J = 4.8 Hz). ¹³C NMR (100 MHz, CDCl₃) δ 22.8, 23.0,

25.2, 35.6, 41.1, 66.0.

4-Methyl-2-(2-methylpropyl)-pentyl Benzoate, 4. Under an argon

atmosphere, a mixture of 3 (1.02 g, 6.43 mmol), 3,5-dihydroxybenzoic

acid (1.04 g, 6.75 mmol), and conc sulfonic acid (0.01 mL) in dry 1,4-

dioxane (13 mL) was heated under reflux for 22 h. After the mixture was

cooled to room temperature, saturated aqueous ammonium chloride

was added. The organic materials were extracted with ethyl acetate. The

organic layer was washed with water and brine and dried over magne-

sium sulfate. The solvent was evaporated under reduced pressure, and

separation by silica gel chromatography gave 4 as white solid (1.38 g,

4.68 mmol, 73%). Mp 98ꢀ100 °C (ethyl acetateꢀhexane). LRMS (EI,

70 eV) m/z: 294 ([M]^þ, 24%), 154 ([M ꢀ C₁₀H₂₀], 100%), 138 ([M ꢀ

C₁₀H₂₀O], 85%). HRMS m/z calcd for C₁₇H₂₆O₄: 294.1831. Found:

294.1840. IR (KBr) 3648 (br), 3304 (br), 2956, 1688, 1607, 1453, 1242,

1150 cm^ꢀ1. ¹H NMR (400 MHz, CDCl₃) δ 0.90 (6H, d, J = 6.4 Hz),

0.91 (6H, d, J = 6.4 Hz), 1.17 (2H, ddd, J = 12.8, 6.4 Hz), 1.28 (2H, ddd,

J = 12.8, 6.4 Hz), 1.70 (2H, ddqq, J = 6.4 Hz), 1.85ꢀ1.94 (1H, m), 4.18

(2H, d, J = 5.2 Hz), 5.22 (2H, s), 6.58 (1H, t, J = 2.4 Hz), 7.11 (2H, d, J =

2.4 Hz). ¹³C NMR (100 MHz, CDCl₃) δ 22.7, 23.0, 25.2, 32.9, 41.6,

68.7, 107.5, 109.1, 132.5, 156.9, 166.8.

consistent with our speculation on the stable double helix

formation with regular alternating arrangement of soft/hard

and/or electron-rich/deﬁcient moieties.

’ CONCLUSIONS

In summary, three series of ethynylhelicene oligomers with

diﬀerent side chains were synthesized: (P)-bD-n with bulky

alkyloxycarbonyl side chains; (P)-S-n with decylsulfanyl side

chains; and (P)-DF-n with alternating decyloxycarbonyl and

perﬂuorooctyl side chains. Double helix formation by these

compounds was compared with that of (P)-D-n. (P)-bD-n with

bulky alkyloxycarbonyl side chains showed a double helix for-

mation similar to that of (P)-D-n, which indicated bulkiness of

side chains to be unimportant. It is considered that the side

chains reside outside the double helix, and the aromatic rings

aggregate via πꢀπ interactions. The double helix of (P)-S-n was

substantially less stable than that of (P)-D-n. The result indicated

the important role of hardness and/or electron-deﬁcient nature

at m-phenylene moieties. (P)-DF-n with alternating perﬂuor-

ooctyl side chains and decyloxycarbonyl side chains did not form

a stable double helix. It was speculated that the regular alternating

soft/hard and/or electron-rich/deﬁcient arrangement of heli-

cenes and m-phenylenes is important for stable double helix

formation. Further systematic studies are required to examine

this speculation. Side chains of ethynylhelicene oligomers play

signiﬁcant roles in determining the stability of double helices.

’ EXPERIMENTAL SECTION

General Methods. ¹H NMR spectra were recorded on a 400 or 600

MHz spectrometer with tetramethylsilane as an internal standard

(δ 0.00). ¹³C NMR spectra were recorded on a 400 or 600 MHz

spectrometer and calibrated using residual solvent CDCl₃(δ 77.0). ¹⁹

F

NMR spectra were recorded on a 400 or 600 MHz spectrometer with

trifluoroacetic acid as an internal or external standard (δ ꢀ79.0).

Chemical shifts are expressed in parts per million (ppm, δ). Coupling

constants are expressed in hertz. FAB mass spectra were recorded using

m-nitrobenzyl alchohol matrix. MALDI-TOF MS spectra were obtained

using R-cyano-4-hydroxycinnamic acid as the matrix. Vapor pressure

osmometry (VPO) was conducted using benzil as a standard. CD and

UVꢀvis spectra were recorded using distilled or spectrophotomeric

grade commercial solvents. The ratio of solvent mixture shows vol/vol.

4-Methyl-2-(2-methylpropyl)pentyl 3,5-Bis(trifluoromethanesulfoxy)-

benzoate, 5. To a solution of 4 (1.15 g, 3.91 mmol) in pyridine (15 mL)

was slowly added trifluoromethanesulfonic acid anhydride (1.6 mL, 9.7

mmol) at ꢀ30 °C. The mixture was gradually warmed to room tempera-

ture and stirred for 3 h. The reaction mixture was diluted with ethyl acetate,

and saturated aqueous ammonium chloride was added. The organic

materials were extracted with ethyl acetate. The organic layer was washed

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with saturated aqueous sodium hydrogencarbonate, water, and brine and

dried over magnesium sulfate. The solvent was evaporated under reduced

pressure, and separation by silica gel chromatography gave 5 as white solid

(2.15 g, 3.84 mmol, 98%). Mp 76ꢀ77 °C (hexaneꢀmethanol). LRMS

(EI, 70 eV) m/z: 401 ([M ꢀ C₁₀H₂₁O]^þ, 54%), 83 ([C₆H₁₁]^þ, 100%).

HRMS (FAB) m/z calcd for C₁₉H₂₃F₆O₈S₂([M ꢀ H]^þ): 557.0733.

Found: 557.0735. IR (KBr) 2960, 1719, 1434, 1250, 1224, 1138 cm^ꢀ1. ¹H

NMR (400 MHz, CDCl₃) δ 0.91 (6H, d, J = 6.8 Hz), 0.93 (6H, d, J =

6.8 Hz), 1.16ꢀ1.30 (4H, m), 1.67ꢀ1.74 (2H, m), 1.89ꢀ1.99 (1H, m),

4.26 (2H, d, J = 5.6 Hz), 7.44 (1H, t, J = 2.4 Hz), 7.98 (2H, d, J = 2.4 Hz).

¹³C NMR (100 MHz, CDCl₃) δ 22.6, 23.0, 25.3, 32.9, 41.8, 70.0, 118.6 (q,

J_CꢀF= 319 Hz), 119.6, 122.4, 134.7, 149.4, 162.9. ¹⁹F NMR (376 MHz,

CDCl₃, trifluoroacetic acid (δ ꢀ79.0) as an external standard) δ ꢀ75.3

(6F, s).

ammonium chloride, and the organic materials were extracted with

toluene. The organic layer was washed with water and brine and dried

over magnesium sulfate. The solvents were evaporated under reduced

pressure, and separation by silica gel chromatography and recycling

GPC gave (P)-bD-2 as a yellow solid (72.4 mg, 0.715 mmol, 95%). Mp

158ꢀ160 °C (tolueneꢀmethanol). [R]²⁷ꢀ591 (c 0.50, CHCl₃).

D

MALDI-TOF MS m/z calcd for C₇₁H₇₀O₂Si₂: 1010.5. Found: 1010.4.

UVꢀvis (CHCl_3,5 ꢁ 10^ꢀ6M) λ_max(ε) 334 nm (1.6 ꢁ 10⁵). CD

(CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 262 nm (115), 296 nm (ꢀ35), 333 nm

(67), 385 nm (ꢀ87). IR (KBr) 2954, 2147, 1724, 1247 cm^ꢀ1. Anal.

(C₇₁H₇₀O₂Si₂) Calcd: C, 84.31; H, 6.98. Found: C, 84.43; H, 7.24. ¹H

NMR (400 MHz, CDCl₃) δ 0.40 (18H, s), 0.98 (6H, d, J = 6.8 Hz), 0.99

(6H, d, J = 6.8 Hz), 1.26 (6H, ddd, J = 13.6, 6.8 Hz), 1.38 (2H, ddd,

J = 13.6, 6.8 Hz), 1.74ꢀ1.84 (2H, m), 1.92 (6H, s), 1.98ꢀ2.05 (1H, m),

4.31 (2H, d, J = 5.6 Hz), 7.43 (2H, d, J = 7.2 Hz), 7.46 (2H, d, J = 7.2 Hz),

7.65 (2H, dd, J = 8.0, 7.2 Hz), 7.70 (2H, dd, J = 8.0, 7.2 Hz), 8.01 (2H, s),

8.05 (2H, s), 8.19 (2H, t, J = 1.2 Hz), 8.35 (2H, d, J = 1.2 Hz), 8.44 (2H,

d, J = 8.0 Hz), 8.54 (2H, d, J = 8.0 Hz). ¹³C NMR (100 MHz, CDCl₃) δ

0.14, 22.8, 23.16, 23.18, 25.4, 33.1, 41.8, 69.0, 89.4, 92.9, 100.2, 103.1,

119.6, 120.3, 123.5, 123.6, 124.3, 126.6, 126.9, 129.1, 129.8, 130.8, 130.9,

131.5, 132.1, 132.31, 132.35, 136.7, 136.8, 138.2, 165.5.

(P)-Building Block with 4-Methyl-2-(2-methylpropyl)-pentanoxy-

carbonyl Side Chains, (P)-bD-1. Under an argon atmosphere, a mixture

of 5 (1.23 g, 2.20 mmol), tris(dibenzylideneacetone)dipalladium(0)

chloroform adduct (45.6 mg, 0.0440 mmol), cuprous iodide (101 mg,

0.0528 mmol), tris(2,4,6-trimethylphenyl)phosphine (103 mg, 0.264

mmol), triphenylphosphine (69.3 mg, 0.264 mmol), tetrabutylammo-

nium iodide (1.30 g, 2.20 mmol), triethylamine (0.70 mL), N,N-

dimethylformamide (6.6 mL), and tetrahydrofuran (2.6 mL) was

freeze-evacuated three times in flask A. In flask B, a solution of

monosilylated ethynylhelicene (P)-6^39a(332 mg, 0.881 mmol) in

tetrahydrofuran (4.0 mL) was freeze-evacuated three times, and the

mixture was slowly added to flask A. The mixture was stirred at room

temperature for 1 h. The reaction was quenched by adding saturated

aqueous ammonium chloride, and the organic materials were extracted

with toluene. The organic layer was washed with water and brine and

dried over magnesium sulfate. The solvents were evaporated under

reduced pressure, and separation by silica gel chromatography and

recycling GPC gave (P)-bD-1 as a yellow solid (588 mg, 0.749 mmol,

Deprotected (P)-Dimer with 4-Methyl-2-(2-methylpropyl)-penta-

noxycarbonyl Side Chains, (P)-bD-2H (Typical Procedure for Desilyla-

tion of (P)-bD-n). To a solution of (P)-bD-2 (60.2 mg, 0.0595 mmol) in

tetrahydrofuran (0.9 mL) was added 1.0 M tetrabutylammonium

fluoride in tetrahydrofuran (0.18 mL, 0.18 mmol) at 0 °C. After 30

min of stirring at the temperature, saturated aqueous ammonium

chloride was added. The organic materials were extracted with toluene.

The organic layer was washed with water and brine and dried over

magnesium sulfate. The solvents were evaporated under reduced

pressure, and silica gel chromatography gave (P)-bD-2H (51.6 mg,

0.0595 mmol, quant). Mp 145ꢀ149 °C, decomp (tolueneꢀmethanol).

[R]²⁷ꢀ582 (c 0.50, CHCl₃). MALDI-TOF MS m/z calcd for

85%). Mp 64ꢀ66 °C (tolueneꢀmethanol). [R]²⁷ꢀ348 (c 0.50,

D

C₆₅H₅₄O₂: 866.4. Found: 866.6. UVꢀvis (CHCl_3,5 ꢁ 10^ꢀ6M) λ_max

(ε) 330 nm (1.5 ꢁ 10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 264 nm

(112), 297 nm (ꢀ37), 329 nm (64), 383 nm (ꢀ84). IR (KBr) 2952,

2205, 1719, 1240 cm^ꢀ1. Anal. (C₆₅H₅₄O₂) calcd for: C, 90.03; H, 6.28.

Found: C, 89.88; H, 6.56. ¹H NMR (400 MHz, CDCl₃) δ 0.98 (6H, d,

J = 6.4 Hz), 0.99 (6H, d, J = 6.4 Hz), 1.26 (6H, ddd, J = 13.6, 6.8 Hz),

1.38 (2H, ddd, J = 13.6, 6.8 Hz), 1.74ꢀ1.82 (2H, m), 1.94 (12H, s),

1.98ꢀ2.05 (1H, m), 3.56 (2H, s), 4.31 (2H, d, J = 5.6 Hz), 7.45 (2H, d,

J = 7.2 Hz), 7.49 (2H, d, J = 7.2 Hz), 7.65 (2H, dd, J = 8.0, 7.2 Hz), 7.71

(2H, dd, J = 8.0, 7.2 Hz), 8.04 (2H, s), 8.07 (2H, s), 8.17 (2H, t, J = 1.6

Hz), 8.34 (2H, d, J = 1.6 Hz), 8.44 (2H, d, J = 8.0 Hz), 8.53 (2H, d, J = 8.0

Hz). ¹³C NMR (100 MHz, CDCl₃) δ 22.8, 23.16, 23.18, 25.4, 33.1, 41.8,

69.0, 81.8, 82.4, 89.3, 93.0, 119.4, 119.7, 123.5, 124.3, 126.8, 126.9, 127.0,

129.19, 129.24, 129.8, 130.4, 130.8, 130.9, 131.5, 132.1, 132.3, 132.4,

136.8, 136.9, 138.2, 165.5.

CHCl₃). MALDI-TOF MS m/z calcd for C₄₅H₄₇F₃O₅SSi: 784.2866.

Found: 784.4. UVꢀvis (CHCl₃, 5 ꢁ 10^ꢀ6M) λ_max(ε) 334 nm (7.3 ꢁ

10⁴). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 261 nm (57), 295 nm (ꢀ19),

331 nm (27), 383 nm (ꢀ44). IR (KBr) 2956, 2148, 1729, 1429,

1248 cm^ꢀ1. Anal. (C₄₅H₄₇F₃O₅SSi) Calcd: C, 68.85; H, 6.03. Found:

1

C, 68.82; H, 6.00. H NMR (400 MHz, CDCl₃) δ 0.39 (9H, s), 0.94

(6H, d, J = 6.4 Hz), 0.96 (6H, d, J = 6.4 Hz), 1.24 (2H, ddd, J = 12.8, 6.4

Hz), 1.32 (2H, ddd, J = 12.8, 6.4 Hz), 1.70ꢀ1.80 (2H, m), 1.92 (6H, s),

1.93 (6H, s), 1.93ꢀ2.01 (1H, m), 4.28 (2H, d, J = 5.6 Hz), 7.45 (1H, d,

J = 8.4 Hz), 7.47 (1H, d, J = 8.4 Hz), 7.67 (1H, dd, J = 8.4 Hz), 7.69 (1H,

dd, J = 8.4 Hz), 7.76 (1H, dd, J = 1.6 Hz), 7.92 (1H, dd, J = 1.6, 1.2 Hz),

8.01 (1H,s), 8.06 (1H, s), 8.35 (1H, dd, J = 1.6, 1.2 Hz), 8.43 (2H, d, J =

8.4 Hz). ¹³C NMR (100 MHz, CDCl₃) δ 0.097, 22.7, 23.06, 23.14, 23.2,

25.3, 33.0, 41.8, 69.5, 91.1, 91.4, 100.3, 102.9, 118.7 (q, J_CꢀF= 319 Hz),

118.9, 120.4, 121.9, 123.3, 123.7, 126.3, 126.9, 127.0, 128.1, 129.2, 129.3,

129.8, 130.3, 130.78, 130.82, 130.9, 131.9, 132.45, 132.53, 133.3, 136.8,

137.0, 137.1, 149.3, 164.2. ¹⁹F NMR (376 MHz, CDCl₃, trifluoroacetic

acid (δꢀ79.0) as an external standard) δ ꢀ75.5 (3F, s).

(P)-Trimer with 4-Methyl-2-(2-methylpropyl)-pentanoxycarbonyl

Side Chains, (P)-bD-3 (Typical Procedure for the Sonogashira Cou-

pling Reaction of (P)-bD-n). Under an argon atmosphere, a mixture of

tris(dibenzylideneacetone)dipalladium(0) chloroform adduct (13.2 mg,

0.0127 mmol), cuprous iodide (29.1 mg, 0.1529 mmol), tris(2,4,6-

trimethylphenyl)phosphine (29.7 mg, 0.764 mmol), triphenylphosphine

(20.1 mg, 0.0764 mmol), tetrabutylammonium iodide (376 mg, 0.255

mmol), triethylamine (0.12 mL), N,N-dimethylformamide (1.2 mL),

and tetrahydrofuran (0.2 mL) was freeze-evacuated three times in flask

A. In flask B, a mixture of diethynylhelicene (P)-7^39a(38.8 mg, 0.127

mmol) and (P)-bD-1 (200 mg, 0.255 mmol) in tetrahydrofuran

(1.0 mL) was freeze-evacuated three times, and the mixture was slowly

added to flask A. The mixture was stirred at 45 °C for 4 h. The reaction

was quenched by adding saturated aqueous ammonium chloride, and the

organic materials were extracted with toluene three times. The com-

bined organic layer was washed with water and brine and dried over

(P)-Dimer with 4-Methyl-2-(2-methylpropyl)-pentanoxycarbonyl

Side Chains, (P)-bD-2. Under an argon atmosphere, a mixture of

tris(dibenzylideneacetone)dipalladium(0) chloroform adduct (8.52

mg, 0.00823 mmol), cuprous iodide (18.8 mg, 0.0988 mmol), tris-

(2,4,6-trimethylphenyl)phosphine (19.2 mg, 0.0494 mmol), triphenyl-

phosphine (13.0 mg, 0.494 mmol), tetrabutylammonium iodide (243

mg, 0.648 mmol), triethylamine (0.11 mL), N,N-dimethylformamide

(1.1 mL), and tetrahydrofuran (0.2 mL) was freeze-evacuated three

times in flask A. In flask B, a mixture of monosilylated ethynylhelicene

(P)-6^39a(56.7 mg, 0.151 mmol) and 5 (42.1 mg, 0.0753 mmol) in

tetrahydrofuran (4.0 mL) was freeze-evacuated three times, and the

mixture was slowly added to flask A. The mixture was stirred at 45 °C for

4 h. The reaction was quenched by adding saturated aqueous

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magnesium sulfate. The solvents were evaporated under reduced

pressure, and separation by silica gel chromatography and recycling

GPC gave (P)-bD-3 as a yellow solid (182 mg, 0.116 mmol, 91%). Mp

126.9, 127.0, 129.1, 129.2, 129.3, 129.8, 130.8, 130.9, 130.93, 131.0, 131.5,

132.1, 132.2, 132.3, 136.7, 136.86, 136.92, 138.2, 165.5.

Deprotected (P)-Tetramer with 4-Methyl-2-(2-methylpropyl)-pen-

tanoxycarbonyl Side Chains, (P)-bD-4H. The compound (45.5 mg,

0.0228 mmol, 98%) was prepared from (P)-bD-4 (50.0 mg, 0.0234

mmol) as a yellow solid. Mp 205ꢀ208 °C, decomp (tolueneꢀmethanol).

175ꢀ177 °C (tolueneꢀmethanol). [R]²⁷ꢀ592 (c 0.50, CHCl₃).

D

MALDI-TOF MS m/z calcd for C₁₁₂H₁₀₈O₄Si₂: 1572.8. Found:

1572.4. UVꢀvis (CHCl_3,5 ꢁ 10^ꢀ6M) λ_max(ε) 335 nm (2.5 ꢁ 10⁵).

CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 264 nm (174), 296 nm (ꢀ52),

[R]²⁷ꢀ572 (c 0.50, CHCl₃). MALDI-TOF MS m/z calcd for

D

C₁₄₇H₁₃₀O₆: 1991.0. Found: 1990.3. UVꢀvis (CHCl_3,5 ꢁ 10^ꢀ6M)

λ_max(ε) 332 nm (2.7 ꢁ 10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 265 nm

(235), 297 nm (ꢀ51), 330 nm (83), 387 nm (ꢀ184). IR (KBr) 2953,

2205, 1724, 1240 cm^ꢀ1. Anal. (C₁₄₇H₁₃₀O₆) Calcd: C, 88.61; H, 6.58.

333 nm (81), 387 nm (ꢀ146). IR (KBr) 2954, 2148, 1724, 1242 cm^ꢀ1

.

Anal. (C₁₁₂H₁₀₈O₄Si₂) Calcd: C, 85.45; H, 6.91. Found: C, 85.56;

H, 6.90. ¹H NMR (400 MHz, CDCl₃) δ 0.40 (18H, s), 0.99 (12H, d,

J = 6.4 Hz), 1.00 (12H, d, J = 6.4 Hz), 1.26 (4H, ddd, J = 12.8, 6.4 Hz),

1.39 (4H, ddd, J = 12.8, 6.4 Hz), 1.75ꢀ1.85 (4H, m), 1.93 (6H, s),

1.95 (6H, s), 1.99 (6H, s), 1.99ꢀ2.05 (2H, m), 4.32 (4H, d, J = 5.6

Hz), 7.44 (2H, d, J = 7.2 Hz), 7.47 (2H, d, J = 7.2 Hz), 7.50 (2H, d, J =

7.2 Hz), 7.66 (2H, dd, J = 8.0, 7.2 Hz), 7.71 (2H, dd, J = 8.0, 7.2 Hz),

7.73 (2H, dd, J = 8.0, 7.2 Hz), 8.02 (2H, s), 8.06 (2H, s), 8.11 (2H, s),

8.20 (2H, dd, J = 1.6, 1.2 Hz), 8.35 (2H, dd, J = 1.2 Hz), 8.36 (2H, dd,

J = 1.6 Hz), 8.44 (2H, d, J = 8.0 Hz), 8.54 (2H, d, J = 8.0 Hz), 8.56

(2H, d, J = 8.0 Hz). ¹³C NMR (100 MHz, CDCl₃) δ 0.13, 22.8, 23.16,

23.23, 25.4, 33.1, 41.9, 69.0, 89.3, 89.4, 92.9, 93.0, 100.2, 103.1, 119.6,

119.8, 120.3, 123.5, 123.6, 123.7, 124.3, 124.4, 126.6, 126.8, 126.9,

127.0, 129.1, 129.2, 129.3, 129.9, 130.8, 130.9, 131.0, 131.5, 132.1,

132.2, 132.4, 136.7, 136.86, 136.92, 138.3, 165.5.

1

Found: C, 88.33; H, 6.83. H NMR (400 MHz, CDCl₃) δ 0.97ꢀ1.01

(36H, m), 1.23ꢀ1.30 (6H, m), 1.35ꢀ1.43 (6H, m), 1.76ꢀ1.83 (6H, m),

1.94 (12H, s), 1.99 (12H, s), 1.99ꢀ2.04 (3H, m), 3.56 (2H, s), 4.31ꢀ4.33

(6H, m), 7.45 (2H, d, J = 6.8 Hz), 7.48 (2H, d, J = 7.2 Hz), 7.51 (4H, d, J =

6.8 Hz), 7.66 (2H, dd, J = 8.0, 7.2 Hz), 7.69ꢀ7.76 (6H, m), 8.05 (2H, s),

8.08 (2H, s), 8.13 (4H, s), 8.19 (2H, dd, J = 1.6 Hz), 8.22 (1H, dd, J = 1.6

Hz), 8.34 (2H, dd, J = 1.6 Hz), 8.35ꢀ8.36 (4H, m), 8.44 (2H, d, J = 8.0

Hz), 8.53ꢀ8.57 (6H, m). ¹³C NMR (100 MHz, CDCl₃) δ 22.8, 23.16,

23.24, 25.4, 33.1, 41.9, 69.0, 81.8, 82.4, 89.3, 92.95, 93.01, 119.4, 119.7,

119.8, 123.5, 123.6, 124.3, 126.8, 126.87, 126.94, 126.99, 127.04, 129.19,

129.24, 129.3, 129.8, 129.9, 130.4, 130.82, 130.84, 130.9, 131.0, 131.1,

131.5, 132.1, 132.2, 132.4, 136.8, 136.9, 137.0, 138.3, 165.5.

(P)-Pentamer with 4-Methyl-2-(2-methylpropyl)-pentanoxycarbo-

nyl Side Chains, (P)-bD-5. The compound (133 mg, 0.0494 mmol, 92%)

was prepared from (P)-bD-3H (76.7 mg, 0.0536 mmol) and (P)-bD-1

(84.2 mg, 0.107 mmol) as a yellow solid. Mp 189ꢀ191 °C

Deprotected (P)-Trimer with 4-Methyl-2-(2-methylpropyl)-penta-

noxycarbonyl Side Chains, (P)-bD-3H. The compound (76.7 mg,

0.0536 mmol, quant) was prepared from (P)-bD-3 (84.5 mg, 0.0536

mmol). Mp 167ꢀ170 °C, decomp (tolueneꢀmethanol). [R]²¹_Dꢀ603

(c 0.50, CHCl₃). MALDI-TOF MS m/z calcd for C₁₀₆H₉₂O₄: 1428.7.

Found: 1428.9. UVꢀvis (CHCl_3,5 ꢁ 10^ꢀ6M) λ_max(ε) 331 nm (2.1 ꢁ

10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 264 nm (175), 297 nm (ꢀ51),

(tolueneꢀmethanol). [R]²¹ꢀ550 (c 0.50, CHCl₃). MALDI-TOF

D

MS m/z calcd for C₁₉₄H₁₈₄O₈Si₂: 2697.4. Found: 2696.9. UVꢀvis

(CHCl_3,5 ꢁ 10^ꢀ6M) λ_max(ε) 336 nm (3.7 ꢁ 10⁵). CD (CHCl_3,

5 ꢁ 10^ꢀ6M) λ (Δε) 264 nm (304), 297 nm (ꢀ83), 334 nm (101),

389 nm (ꢀ248). IR (KBr) 2954, 2150, 1726, 1240 cm^ꢀ1. Anal.

(C₁₉₄H₁₈₄O₈Si₂) Calcd: C, 86.31; H, 6.87. Found: C, 86.37; H, 7.10.

¹H NMR (400 MHz, CDCl₃) δ 0.39 (18H, s), 0.97ꢀ1.01 (48H, m),

1.22ꢀ1.30 (8H, m), 1.35ꢀ1.43 (8H, m), 1.74ꢀ1.83 (8H, m), 1.93 (6H,

s), 1.94 (6H, s), 1.99 (12H, s), 2.00 (6H, s), 2.00ꢀ2.04 (4H, m),

4.30ꢀ4.33 (8H, m), 7.44 (2H, d, J = 6.8 Hz), 7.47 (2H, d, J = 7.2 Hz),

7.49ꢀ7.52 (6H, m), 7.66 (2H, dd, J = 8.0, 7.2 Hz), 7.69ꢀ7.76 (8H, m),

8.01 (2H,s), 8.06 (2H, s), 8.11ꢀ8.12 (6H, m), 8.20 (2H, dd, J = 1.6, 1.2

Hz), 8.21 (2H, dd, J = 1.6, 1.2 Hz), 8.34 (2H, dd, J = 1.6, 1.2 Hz),

330 nm (71), 387 nm (ꢀ136). IR (KBr) 2954, 2208, 1724, 1240 cm^ꢀ1

.

Anal. (C₁₀₆H₉₂O₄) Calcd: C, 89.04; H, 6.49. Found: C, 89.04; H, 6.43.

¹H NMR (400 MHz, CDCl₃) δ 0.98 (12H, d, J = 6.8 Hz), 0.99 (12H, d,

J = 6.4 Hz), 1.26 (4H, ddd, J = 14.7, 7.0 Hz), 1.39 (4H, ddd, J = 13.6, 6.8

Hz), 1.75ꢀ1.85 (4H, m), 1.95 (12H, s), 1.99 (6H, s), 1.99ꢀ2.05 (2H,

m), 3.56 (2H, s), 4.31 (4H, d, J = 5.6 Hz), 7.45ꢀ7.51 (6H, m), 7.66 (2H,

dd, J = 8.0, 7.2 Hz), 7.72 (2H, dd, J = 8.0, 7.2 Hz), 7.73 (2H, dd, J = 8.0,

7.2 Hz), 8.05 (2H, s), 8.08 (2H, s), 8.12 (2H, s), 8.19 (2H, dd, J = 1.6

Hz), 8.34 (2H, dd, J = 1.6 Hz), 8.36 (2H, dd, J = 1.6 Hz), 8.44 (2H, d, J =

8.0 Hz), 8.54 (2H, d, J = 8.0 Hz), 8.55 (2H, d, J = 8.0 Hz). ¹³C NMR (100

MHz, CDCl₃) δ 22.8, 23.17, 23.19, 23.24, 25.4, 33.1, 41.9, 69.0, 81.8,

82.4, 89.3, 92.96, 93.01, 119.4, 119.75, 119.83, 123.5, 124.3, 126.8,

126.86, 126.94, 126.99, 127.03, 129.2, 129.25, 129.31, 129.8, 129.9,

130.4, 130.8, 130.9, 131.0, 131.1, 131.5, 132.1, 132.2, 132.4, 136.8, 136.9,

137.0, 138.3, 165.5.

8.35ꢀ8.36 (6H, m), 8.43 (2H, d, J = 7.6 Hz), 8.53ꢀ8.57 (8H, m). ¹³

C

NMR (100 MHz, CDCl₃) δ 0.12, 22.8, 23.16, 23.23, 25.4, 33.1, 41.9,

69.0, 89.3, 89.4, 92.9, 93.0, 100.2, 103.1, 119.6, 119.8, 120.3, 123.5,

123.58, 123.65, 124.3, 126.6, 126.8, 126.9, 127.0, 129.1, 129.2, 129.3,

129.9, 130.8, 130.9, 131.0, 131.47, 131.48, 132.1, 132.2, 132.3, 136.7,

136.86, 136.93, 138.2, 165.5.

(P)-Tetramer with 4-Methyl-2-(2-methylpropyl)-pentanoxycarbo-

nyl Side Chains, (P)-bD-4. The compound (86.2 mg, 0.0403 mmol,

92%) was prepared from (38.0 mg, 0.0438 mmol) and (P)-bD-1 (68.8 mg,

0.0877 mmol) as a yellow solid. Mp 187ꢀ189 °C (tolueneꢀmethanol).

(P)-Hexamer with 4-Methyl-2-(2-methylpropyl)-pentanoxycarbo-

nyl Side Chains, (P)-bD-6. The compound (147 mg, 0.0451 mmol,

94%) was prepared from (P)-bD-4H (96.0 mg, 0.0482 mmol) and (P)-

bD-1 (75.6 mg, 0.0964 mmol) as a yellow solid. Mp 190ꢀ193 °C

(tolueneꢀmethanol). [R]²⁷_Dꢀ506 (c 0.50, CHCl₃). MALDI-TOF MS

m/z calcd for C₂₃₅H₂₂₂O₁₀Si₂: 3259.6. Found: 3260.5. UVꢀvis (CHCl_3,

5 ꢁ 10^ꢀ6M) λ_max(ε) 336 nm (4.3 ꢁ 10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ

(Δε) 264 nm (354), 297 nm (ꢀ88), 336 nm (111), 389 nm (ꢀ295). IR

(KBr) 2954, 2148, 1724, 1239 cm^ꢀ1. Anal. (C₂₃₅H₂₂₂O₁₀Si₂) Calcd: C,

86.52; H, 6.86. Found: C, 86.35; H, 7.11. ¹H NMR (400 MHz, CDCl₃)

δ 0.39 (18H, s), 0.97ꢀ1.01 (60H, m), 1.23ꢀ1.35 (10H, m), 1.36ꢀ1.43

(10H, m), 1.74ꢀ1.85 (10H, m), 1.92 (6H, s), 1.94 (6H, s), 1.98ꢀ2.06

(29H, m), 4.30ꢀ4.32 (10H, m), 7.44 (2H, d, J = 7.2 Hz), 7.46ꢀ7.51

(10H, m), 7.66 (2H, dd, J = 8.0, 7.2 Hz), 7.69ꢀ7.75 (10H, m), 8.01 (2H,

s), 8.05 (2H, s), 8.10 (4H, s), 8.11 (4H, m), 8.19 (1H, dd, J = 1.6 Hz),

8.20ꢀ8.22 (4H, m), 8.33 (2H, dd, J = 1.6 Hz), 8.34ꢀ8.36 (8H, m), 8.43

(2H, d, J = 8.0 Hz), 8.53ꢀ8.57 (10H, m). ¹³C NMR (100 MHz, CDCl₃)

δ 0.12, 22.8, 23.16, 23.25, 25.4, 29.7, 33.1, 41.8, 69.0, 89.3, 89.4, 92.9,

[R]²⁷ꢀ566 (c 0.50, CHCl₃). MALDI-TOF MS m/z calcd for

D

C₁₅₃H₁₄₆O₆Si₂: 2135.1. Found: 2135.6. UVꢀvis (CHCl_3,5 ꢁ 10^ꢀ6M)

λ_max(ε) 335 nm (2.9 ꢁ 10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 264 nm

(237), 296 nm (ꢀ66), 333 nm (87), 387 nm (ꢀ193). IR (KBr) 2953,

2146, 1724, 1239 cm^ꢀ1. Anal. (C₁₅₃H₁₄₆O₆Si₂) Calcd: C, 85.99; H, 6.89.

Found: C, 85.97; H, 7.00. ¹H NMR (400 MHz, CDCl₃) δ 0.40 (18H, s),

0.98ꢀ1.02 (36H, m), 1.23ꢀ1.31 (6H, m), 1.36ꢀ1.44 (6H, m), 1.75ꢀ1.84

(6H, m), 1.94 (6H, s), 1.95 (6H, m), 2.00 (12H, s), 2.00ꢀ2.05 (3H, m),

4.32ꢀ4.34 (6H, m), 7.45 (2H, d, J = 7.2 Hz), 7.48 (2H, d, J = 7.2 Hz), 7.51

(4H, d, J = 7.2 Hz), 7.66 (2H, dd, J = 8.0, 7.2 Hz), 7.70ꢀ7.76 (6H, m), 8.02

(2H, s), 8.06 (2H, s), 8.12 (4H, s), 8.21 (2H, dd, J = 1.6 Hz), 8.22 (1H, dd,

J=1.6 Hz), 8.35(2H, dd, J= 1.6 Hz), 8.37 (4H, dd, J= 1.6 Hz), 8.44 (2H, d,

J = 7.2 Hz), 8.54ꢀ8.58 (6H, m). ¹³C NMR (100 MHz, CDCl₃) δ 0.13,

22.8, 23.15, 23.25, 25.4, 33.1, 41.8, 69.0, 89.3, 89.4, 92.9, 93.0, 100.2, 103.1,

119.6, 119.8, 120.3, 123.5, 123.59, 123.64, 124.3, 124.34, 124.4, 126.6, 126.8,

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ARTICLE

93.0, 100.2, 103.0, 119.6, 119.8, 120.3, 123.5, 123.57, 123.64, 124.3,

126.6, 126.8, 126.9, 127.0, 129.1, 129.2, 129.3, 129.8, 130.8, 130.9, 131.0,

131.4, 132.1, 132.2, 132.3, 136.7, 136.87, 136.92, 138.2, 165.5.

mg, 1.86 mmol), triethylamine (0.78 mL), and N,N-dimethylformamide

(7.8 mL) was freeze-evacuated three times in flask A. In flask B, a

solution of monosilylated ethynylhelicene (P)-6^39a(350 mg, 0.930

mmol) and 11 (1.02 g, 1.86 mmol) in N,N-dimethylformamide

(7.8 mL) was freeze-evacuated three times, and the mixture was slowly

added to flask A. The mixture was stirred at room temperature for 1 h.

The reaction was quenched by adding saturated aqueous ammonium

chloride, and the organic materials were extracted with toluene. The

organic layer was washed with water and brine and dried over magne-

sium sulfate. The solvents were evaporated under reduced pressure, and

separation by silica gel chromatography and recycling GPC gave (P)-S-1

as a yellow solid (635 mg, 0.821 mmol, 88%). Mp 58ꢀ59 °C. (diethyl

etherꢀmethanol). [R]²⁶_Dꢀ297 (c 0.10, CHCl₃). LRMS (EI, 70 eV) m/

z: 772 ([M]^þ, 100%). HRMS m/z calcd for C₄₄H₄₇F₃O₃S₂Si: 772.2688.

Found: 772.2674. IR (KBr) 2925, 2210, 2148, 1596, 1246, 1215

1139 cm^ꢀ1. Anal. (C₄₄H₄₇F₃O₃S₂Si) Calcd: C, 68.36; H, 6.13. Found:

5-Decylsulfanyl-1,3-dimethoxybenzene, 9. Under an argon atmo-

sphere, a mixture of potassium carbonate (3.90 g, 28.2 mmol), 3,5-

dimethoxybenzenethiol 8 (2.67 g, 15.7 mmol), acetone (64 mL), and

1-bromodecane (6.6 mL, 31.4 mmol) was heated under reflux for 2 h.

After insoluble materials were filtered, the solvent was evaporated under

reduced pressure. Separation by silica gel chromatography gave 9 as

colorless oil (4.71 g, 15.2 mmol, 97%). LRMS (EI, 70 eV) m/z: 310

([M]^þ, 27%), 170 ([M ꢀ C₁₀H₂₀]^þ, 100%). HRMS m/z calcd for

C₁₈H₃₀O₂S: 310.1966. Found: 310.1945. IR (neat) 2923, 1585, 1455,

1417, 1204, 1157 cm^ꢀ1. Anal. (C₁₈H₃₀O₂S) Calcd: C, 69.63; H, 9.74.

Found: C, 69.67; H, 9.71. ¹H NMR (400 MHz, CDCl₃) δ 0.88 (3H, t, J =

6.8 Hz), 1.26ꢀ1.30 (12H, m), 1.37ꢀ1.45 (2H, m), 1.66 (2H, quint, J =

7.2 Hz), 2.90 (2H, t, J = 7.2 Hz), 3.77 (6H, s), 6.26 (1H, t, J = 2.0 Hz),

6.46 (2H, d, J = 3.6 Hz). ¹³C NMR (100 MHz, CDCl₃) δ 14.1, 22.6,

28.9, 29.0, 29.1, 29.3, 29.48, 29.51, 31.8, 33.1, 55.3, 97.8, 106.0,

139.2, 160.8.

1

C, 68.28; H, 6.21. H NMR (400 MHz, CDCl₃) δ 0.38 (9H, s), 0.87

(3H, t, J = 7.2 Hz), 1.23ꢀ1.36 (12H, m), 1.43ꢀ1.51 (2H, m), 1.72 (2H,

quint, J = 7.2 Hz), 1.927 (3H, s), 1.931 (3H, s), 3.01 (2H, t, J = 7.2 Hz),

7.17 (1H, t, J = 2.0 Hz), 7.33 (1H, dd, J = 2.0 Hz, 1.6 Hz), 7.45 (1H, d, J =

6.8 Hz), 7.46 (1H, d, J = 6.8 Hz), 7.57 (1H, t, J = 1.6 Hz), 7.65 (1H, dd,

J = 8.0, 6.8 Hz), 7.69 (1H, dd, J = 8.0, 6.8 Hz), 8.01 (1H, s), 8.04 (1H, s),

8.42 (1H, d, J = 8.0 Hz), 8.43 (1H, d, J = 8.0 Hz). ¹³C NMR (100 MHz,

CDCl₃) δ 0.37, 14.1, 22.7, 23.13, 23.14, 28.6, 28.8, 29.1, 29.3, 29.46,

29.51, 31.9, 33.0, 90.1, 92.0, 100.3, 103.0, 118.7 (q, J_CꢀF= 318.3 Hz),

119.2, 120.0, 120.4, 120.7, 123.4, 123.5, 123.7, 125.9, 126.8, 126.9, 127.0,

129.16, 129.24, 129.8, 130.0, 130.3, 130.8, 130.92, 130.94, 131.9, 132.4,

136.8, 136.9, 141.5, 149.4. ¹⁹F NMR (376 MHz, CDCl₃) δ ꢀ75.4 (3F, s).

(P)-Dimer with Decylthio Side Chains, (P)-S-2. Under an argon

atmosphere, a mixture of tris(dibenzylidenacetone)dipalladium(0)-

chloroform adduct (7.8 mg, 0.0076 mmol), cuprous iodide (17.3 mg,

0.0908 mmol), trimesitylphosphine (17.6 mg, 0.0454 mmol), triphe-

nylphosphine (11.9 mg, 0.0454 mmol), tetrabutylammonium iodide

(224 mg, 0.605 mmol), triethylamine (0.18 mL), and N,N-dimethylfor-

mamide (1.3 mL) was freeze-evacuated three times in flask A. In flask B,

a solution of monosilylated ethynylhelicene (P)-6^39a(114 mg, 0.303

mmol) and 11 (82.6 mg, 0.151 mmol) in N,N-dimethylformamide

(2.3 mL) was freeze-evacuated three times, and the mixture was slowly

added to flask A. The mixture was stirred at the room temperature for 1

h. The reaction was quenched by adding saturated aqueous ammonium

chloride, and the organic materials were extracted with toluene. The

organic layer was washed with water and brine and dried over magne-

sium sulfate. The solvents were evaporated under reduced pressure, and

separation by silica gel chromatography and recycling GPC gave (P)-S-2

as a yellow solid (135 mg, 0.135 mmol, 89%). Mp 126ꢀ128 °C.

5-Decylsulfanyl-1,3-dihydroxybenzene, 10. Under an argon atmo-

sphere, to a solution of 9 (4.63 g, 16.4 mmol) in dichloromethane

(42 mL) was slowly added boron tribromide (1 M dichloromethane

solution, 33 mL, 32.8 mmol) at ꢀ78 °C. Then the mixture was warmed

to room temperature and stirred for 36 h. The reaction was quenched by

slowly adding water (84 mL) at 0 °C, and the organic materials were

extracted with ethyl acetate. The organic layer was washed with water

and brine and dried over magnesium sulfate. The solvents were

evaporated under reduced pressure, and separation by silica gel chro-

matography gave 10 as white solid (3.91 g, 13.8 mmol, 84%). Mp

94ꢀ96 °C (ethyl acetate). LRMS (EI, 70 eV) m/z: 282 ([M]^þ, 29%),

142 ([M ꢀ C₁₀H₂₀]^þ, 100%). HRMS m/z calcd for C₁₆H₂₆O₂S:

282.1653. Found: 282.1644. IR (KBr) 3252, 2920, 1624, 1594, 1485,

1471 cm^ꢀ1. Anal. (C₁₆H₂₆O₂S) Calcd: C, 68.04; H, 9.28. Found: C,

67.97; H, 9.14. ¹H NMR (400 MHz, CDCl₃ꢀCD₃OD) δ 0.89 (3H, t, J =

6.8 Hz), 1.23ꢀ1.34 (12H, m), 1.38ꢀ1.46 (2H, m), 1.65 (2H, quint, J =

7.6 Hz), 2.88 (2H, t, J = 7.6 Hz), 6.13 (1H, t, J = 2.0 Hz), 6.32 (2H, d, J =

2.0 Hz) 7.56 (2H, s). ¹³C NMR (100 MHz, CDCl₃ꢀCD₃OD) δ 13.2,

22.1, 28.3, 28.59, 28.63, 28.7, 29.0, 31.3, 32.3, 99.7, 106.2, 138.2, 157.6.

5-Decylsulfanyl-1,3-bis(trifluoromethanesulfonyloxy)benzene, 11.

Under an argon atmosphere, to a mixture of 10 (3.75 g, 13.3 mmol),

dichloromethane (13 mL), and triethylamine (13 mL) was slowly added

trifluoromethanesulfonic acid unhydride (7.4 mL, 43.8 mmol)

at ꢀ40 °C. The reaction mixture was warmed to room temperature,

and was stirred for 3 h. The reaction was quenched by adding saturated

aqueous ammonium chloride, and the organic materials were extracted

with ethyl acetate. The organic layer was washed with saturated aqueous

sodium hydrogencarbonate, brine, and dried over magnesium sulfate.

The solvent was evaporated under reduced pressure, and separation by

silica gel chromatography gave 11 as colorless oil (6.44 g, 11.8 mmol,

89%). LRMS (EI, 70 eV) m/z: 546 ([M]^þ, 100%), 406 ([M ꢀ

C₁₀H₂₀]^þ, 69%), 149 ([CF₃O₃S]^þ, 28%). HRMS m/z calcd for

C₁₈H₂₄F₆O₆S₃: 546.0639. Found: 546.0628. IR (neat) 2928, 1604,

1578, 1431, 1213, 1139 cm^ꢀ1. Anal. (C₁₈H₂₄F₆O₆S₃) Calcd: C,

39.55; H, 4.43. Found: C, 39.79; H, 4.46. ¹H NMR (400 MHz, CDCl₃)

δ 0.88 (3H, t, J = 7.2 Hz), 1.23ꢀ1.34 (12H, m), 1.41ꢀ1.48 (2H, m),

1.70 (2H, quint, J = 7.2 Hz), 2.97 (2H, t, J = 7.2 Hz), 6.96 (1H, t, J = 2.0

Hz), 7.16 (2H, d, J = 2.0 Hz). ¹³C NMR (100 MHz, CDCl₃) δ 14.0, 22.7,

28.3, 28.8, 29.1, 29.3, 29.4, 29.5, 31.9, 32.6, 111.3, 118.6 (q, J_CꢀF= 319.2

Hz), 119.3, 144.3, 149.5. ¹⁹F NMR (376 MHz, CDCl₃) δ ꢀ75.6 (6F, s).

(P)-Building Block with Decylthio Side Chains, (P)-S-1. Under an

argon atmosphere, a mixture of tris(dibenzylidenacetone)dipalladium-

(0)-chloroform adduct (24.1 mg, 0.0232 mmol), cuprous iodide (53.1

mg, 0.279 mmol), trimesitylphosphine (54.2 mg, 0.139 mmol), triphe-

nylphosphine (36.6 mg, 0.139 mmol), tetrabutylammonium iodide (687

(chloroformꢀmethanol). [R]²⁷ꢀ629 (c 0.10, CHCl₃). HRMS

D

(FAB) m/z calcd for C₇₀H₇₀SSi₂: 998.4737. Found: 998.4723. UVꢀvis

(CHCl₃, 5 ꢁ 10^ꢀ6M) λ_max(ε) 333 nm (1.6 ꢁ 10⁵). CD (CHCl₃, 5 ꢁ

10^ꢀ6M) λ (Δε) 297 nm (ꢀ44), 332 nm (54), 384 nm (ꢀ88). IR (KBr)

2925, 2147, 1248 cm^ꢀ1. Anal. (C₇₀H₇₀SSi₂) Calcd: C, 84.11; H, 7.06.

Found: C, 83.92; H, 7.05. ¹H NMR (400 MHz, CDCl₃) δ 0.39 (18H, s),

0.86 (3H, t, J = 7.2 Hz), 1.23ꢀ1.38 (12H, m), 1.46ꢀ1.54 (2H, m), 1.75

(2H, quint, J = 7.2 Hz), 1.93 (6H, s), 1.94 (6H, s), 3.06 (2H, t, J = 7.2

Hz), 7.45 (2H, d, J = 7.2 Hz), 7.47 (2H, d, J = 7.2 Hz), 7.64 (2H, d, J = 1.6

Hz), 7.66 (2H, dd, J = 8.0, 7.2 Hz), 7.70 (2H, dd, J = 8.0, 7.2 Hz), 7.82

(1H, t, J = 1.6 Hz), 8.03 (2H, s), 8.06 (2H, s), 8.43 (2H, d, J = 8.0 Hz),

8.52 (2H, d, J = 8.0 Hz). ¹³C NMR (100 MHz, CDCl₃) δ 0.13, 14.1,

22.7, 23.15, 23.18, 28.9, 29.0, 29.2, 29.3, 29.5, 29.6, 31.9, 33.4, 88.8, 93.5,

100.1, 103.1, 119.9, 120.3, 123.6, 123.7, 124.3, 126.6, 126.9, 129.1, 129.2,

129.7, 129.9, 130.9, 130.97, 131.00, 131.1, 132.1, 132.3, 136.7,

136.9, 138.5.

Deprotected (P)-Dimer with Decylthio Side Chains, (P)-S-2H

(Typical Procedure for Desilylation of (P)-S-n). To a solution of (P)-

S-2 (106 mg, 0.106 mmol) in tetrahydrofuran (3.5 mL) was added

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ARTICLE

tetrabutylammonium fluoride (1.0 M tetrahydrofuran solution, 0.32 mL,

0.32 mmol) at 0 °C, and the mixture was stirred at the temperature for 30

min. The reaction was quenched by adding saturated aqueous ammo-

nium chloride, and the organic materials were extracted with toluene.

The organic layer was washed with water and brine and dried over

magnesium sulfate. The solvents were evaporated under reduced

pressure, and separation by silica gel chromatography gave (P)-S-2H

as a yellow solid (89.2 mg, 0.104 mmol, 98%). Mp 115ꢀ117 °C

3.06 (4H, t, J=7.2Hz), 3.56(2H, s), 7.45(2H, d,J= 7.2 Hz), 7.47 (2H, d, J=

7.2 Hz), 7.49 (2H, d, J = 7.2 Hz), 7.62ꢀ7.74 (10H, m), 7.83 (2H, t, J = 1.6

Hz), 8.04 (2H, s), 8.06 (2H, s), 8.08 (2H, s), 8.44 (2H, d, J = 8.0 Hz), 8.53

(2H, d,J= 8.0 Hz), 8.54 (2H, d, J=8.0Hz).¹³C NMR (100 MHz, CDCl₃) δ

14.1, 22.7, 23.18, 23.24, 28.9, 29.0, 29.2, 29.3, 29.5, 29.6, 31.9, 33.4, 81.8, 82.4,

88.7, 88.8, 93.5, 119.3, 119.96, 119.99, 123.5, 123.6, 124.3, 126.6, 126.7,

126.90, 126.94, 129.17, 129.21, 129.24, 129.6, 129.7, 130.4, 130.8, 130.88,

130.92, 131.0, 131.1, 131.8, 132.2, 132.3.

(chloroformꢀmethanol). [R]²⁷ꢀ612 (c 0.10, CHCl₃). HRMS

(P)-Tetramer with Decylthio Side Chains, (P)-S-4. The compound

(154 mg, 0.0731 mmol, 81%) was prepared from (P)-S-2H (77.7 mg,

0.0909 mmol) and (P)-S-1 (141 mg, 0.182 mmol) as a yellow solid. Mp

D

(FAB) m/z calcd for C₆₄H₅₄S: 854.3946. Found: 854.3948. IR (KBr)

3290, 2924 cm^ꢀ1. ¹H NMR (400 MHz, CDCl₃) δ 0.85 (3H, t, J = 6.8

Hz), 1.24ꢀ1.36 (12H, m), 1.46ꢀ1.54 (2H, m), 1.76 (2H, quint, J = 7.2

Hz), 1.95 (12H, s), 3.06 (2H, t, J = 7.2 Hz), 3.56 (2H, s), 7.46 (2H, d, J =

7.2 Hz), 7.48 (2H, d, J = 7.2 Hz), 7.64 (2H, d, J = 1.6 Hz), 7.66 (2H, dd,

J = 7.6, 7.2 Hz), 7.71 (2H, dd, J = 7.6, 7.2 Hz), 7.82 (1H, t, J = 1.6 Hz),

8.06 (2H, s), 8.08 (2H, s), 8.45 (2H, d, J = 7.6 Hz), 8.52 (2H, d, J = 7.6

Hz). ¹³C NMR (100 MHz, CDCl₃) δ 14.1, 22.7, 23.2, 28.9, 29.0, 29.2,

29.3, 29.5, 29.6, 31.9, 33.4, 81.8, 82.4, 88.7, 93.5, 119.3, 120.0, 123.5,

123.6, 124.3, 126.7, 126.9, 127.0, 129.19, 129.22, 129.6, 130.4, 130.87,

130.90, 130.94, 131.2, 131.8, 132.2, 132.3, 136.8, 136.9, 138.6.

139ꢀ141 °C (chloroformꢀmethanol). [R]²⁷_Dꢀ604 (c 0.10, CHCl₃).

MALDI-TOF MS m/z calcd for

C

¹³CH₁₄₆S₃Si₂: 2100.0. Found:

149

12

2100.9. UVꢀvis (CHCl₃, 5 ꢁ 10^ꢀ6M) λ_max(ε) 335 nm (3.1 ꢁ 10⁵).

CD (CHCl₃, 5 ꢁ 10^ꢀ6M) λ (Δε) 297 nm (ꢀ90), 335 nm (70), 387 nm

(ꢀ186). IR (KBr) 2923, 2146, 1248 cm^ꢀ1. Anal. (C₁₅₀H₁₄₆S₃Si₂)

1

Calcd: C, 85.74; H, 7.00. Found: C, 85.70; H, 7.19. H NMR (400

MHz, CDCl₃) δ0.39 (18H, s), 0.85 (9H, t, J= 7.2 Hz), 1.22ꢀ1.40 (36H, m),

1.47ꢀ1.54 (6H, m), 1.72ꢀ1.80 (6H, m), 1.93 (6H, s), 1.94 (6H, s),

1.99 (12H, s), 3.07 (4H, t, J = 7.2 Hz), 3.08 (2H, t, J = 7.2 Hz), 7.45

(2H, d, J = 7.2 Hz), 7.47 (2H, d, J = 7.2 Hz), 7.50 (4H, d, J = 7.2 Hz),

7.64ꢀ7.75 (14H, m), 7.83 (2H, t, J = 1.6 Hz), 7.85 (1H, t, J = 1.6 Hz),

8.03 (2H, s), 8.06 (2H, s), 8.12 (4H, s), 8.43 (2H, d, J = 8.0 Hz),

8.50ꢀ8.56 (6H, m). ¹³C NMR (100 MHz, CDCl₃) δ 0.12, 14.1, 22.7,

23.15, 23.18, 23.24, 28.9, 29.0, 29.2, 29.3, 29.5, 29.6, 31.9, 33.4, 88.8,

93.45, 93.54, 100.1, 103.1, 119.8, 120.0, 120.2, 123.57, 123.64, 124.3,

126.5, 126.6, 126.86, 126.93, 129.1, 129.16, 129.24, 129.67, 129.69,

129.9, 130.8, 130.95, 130.98, 131.1, 131.8, 132.1, 132.2, 132.3, 136.7,

136.8, 136.9, 138.5.

(P)-Trimer with Decylthio Side Chains, (P)-S-3 (Typical Procedure

for the Sonogashira Coupling Reaction of (P)-S-n). Under an argon

atmosphere, a mixture of (P)-S-1 (147 mg, 0.190 mmol), tris-

(dibenzylidenacetone)dipalladium(0)-chloroform adduct (9.8 mg,

0.0095 mmol), cuprous iodide (21.7 mg, 0.114 mmol), trimesitylpho-

sphine (22.1 mg, 0.0570 mmol), triphenylphosphine (14.9 mg, 0.0570

mmol), tetrabutylammonium iodide (281 mg, 0.760 mmol), triethyla-

mine (0.11 mL), N,N-dimethylformamide (0.77 mL), and tetrahydro-

furan (0.39 mL) was freeze-evacuated three times in flask A. In flask B, a

solution of diethynylhelicene (P)-7^39a(28.9 mg, 0.0950 mmol) in

tetrahydrofuran (1.2 mL) was freeze-evacuated three times, and the

mixture was slowly added to flask A. The mixture was stirred at 45 °C for

1.5 h. The reaction was quenched by adding saturated aqueous

ammonium chloride, and the organic materials were extracted with

toluene three times. The combined organic layer was washed with water

and brine and dried over magnesium sulfate. The solvents were

evaporated under reduced pressure, and separation by silica gel chro-

matography and recycling GPC gave (P)-S-3 as a yellow solid (123 mg,

0.0792 mmol, 83%). Mp 137ꢀ139 °C (chloroformꢀmethanol).

Deprotected (P)-Tetramer with Decylthio Side Chains, (P)-S-4H.

The compound (140 mg, 0.0715 mmol, 98%) was prepared from (P)-S-

4 (154 mg, 0.0732 mmol) as a yellow solid. Mp 126ꢀ128 °C

(chloroformꢀmethanol). [R]²⁶ꢀ566 (c 0.10, CHCl₃). MALDI-

12

TOF MS m/z calcd for

C

¹^D³CH₁₃₀S₃: 1955.9. Found: 1955.6. IR

143

(KBr) 3292, 2924 cm^ꢀ1. Anal. (C₁₄₄H₁₃₀S₃) Calcd: C, 88.39; H, 6.70.

Found: C, 88.21; H, 6.54. ¹H NMR (400 MHz, CDCl₃) δ 0.85 (9H, t, J =

7.2 Hz), 1.22ꢀ1.38 (36H, m), 1.46ꢀ1.53 (6H, m), 1.72ꢀ1.79 (6H, m),

1.95 (12H, s), 1.98 (12H, s), 3.06 (4H, t, J = 7.2 Hz), 3.07 (2H, t, J = 7.2

Hz), 3.56 (2H, s), 7.45ꢀ7.51 (8H, m), 7.63ꢀ7.74 (14H, m), 7.83 (2H, t,

J = 1.2 Hz), 7.84 (1H, t, J = 1.2 Hz), 8.05 (2H, s), 8.07 (2H, s), 8.11 (4H,

s), 8.44 (2H, d, J = 8.0 Hz), 8.51ꢀ8.56 (6H, m). ¹³C NMR (100 MHz,

CDCl₃) δ 14.1, 22.7, 23.19, 23.24, 28.9, 29.0, 29.2, 29.3, 29.5, 29.6, 31.9,

33.4, 81.8, 82.4, 88.7, 93.5, 119.3, 119.97, 120.01, 123.5, 123.6, 124.3,

126.67, 126.70, 126.9, 127.0, 129.18, 129,21, 129.24, 129.6, 129.7, 130.4,

130.86, 130.89, 130.93, 131.0, 131.1, 131.8, 132.2, 132.3, 136.8,

136.9, 138.6.

[R]²⁷ꢀ624 (c 0.10, CHCl₃). MALDI-TOF MS m/z calcd for

D

12

C

¹³CH₁₀₈S₂Si₂: 1549.7. Found: 1550.2. UVꢀvis (CHCl₃, 5 ꢁ

109

10^ꢀ6M) λ_max(ε) 334 nm (2.3 ꢁ 10⁵). CD (CHCl₃, 5 ꢁ 10^ꢀ6M) λ

(Δε) 297 nm (ꢀ60), 334 nm (64), 386 nm (ꢀ129). IR (KBr) 2923,

2146, 1248 cm^ꢀ1. Anal. (C₁₁₀H₁₀₈S₂Si₂) Calcd: C, 85.22; H, 7.02.

Found: C, 85.04; H, 7.16. ¹H NMR (400 MHz, CDCl₃) δ 0.39 (18H, s),

0.86 (6H, t, J = 7.2 Hz), 1.23ꢀ1.40 (24H, m), 1.47ꢀ1.54 (4H, m), 1.76

(4H, quint, J = 7.2 Hz), 1.94 (6H, s), 1.95 (6H, s), 1.99 (6H, s), 3.07

(4H, t, J = 7.2 Hz), 7.45 (2H, d, J = 7.2 Hz), 7.47 (2H, d, J = 7.2 Hz), 7.50

(2H, d, J = 7.2 Hz), 7.64ꢀ7.75 (10H, m), 7.83 (2H, t, J = 1.6 Hz), 8.03

(2H, s), 8.06 (2H, s), 8.12 (2H, s), 8.43 (2H, d, J = 7.6 Hz), 8.52 (2H, d,

J = 7.6 Hz), 8.54 (2H, d, J = 7.6 Hz). ¹³C NMR (100 MHz, CDCl₃) δ

0.13, 14.1, 22.7, 23.15, 23.18, 23.23, 28.9, 29.0, 29.2, 29.3, 29.5, 29.6,

31.9, 33.4, 88.7, 88.8, 93.4, 93.5, 100.1, 103.1, 119.8, 120.0, 120.2, 123.57,

123.64, 124.30, 124.32, 126.5, 126.6, 126.87, 126.94, 129.1, 129.16,

129.24, 129.7, 129.9, 130.8, 130.96, 130.99, 131.1, 131.8, 132.1, 132.2,

132.3, 136.7, 136.8, 136.9, 138.5.

(P)-Pentamer with Decylthio Side Chains, (P)-S-5. The compound

(198 mg, 0.0745 mmol, 81%) was prepared from (P)-bD-3H (130 mg,

0.0925 mmol) and (P)-bD-1 (143 mg, 0.185 mmol) as a yellow solid.

Mp 143ꢀ145 °C (chloroformꢀmethanol). [R]²⁷ꢀ617 (c 0.10,

D

12

CHCl₃). MALDI-TOF MS m/z calcd for

C

¹³C₂H₁₈₄S₄Si₂:

188

2651.3. Found: 2650.5. UVꢀvis (CHCl₃, 5 ꢁ 10^ꢀ6M) λ_max(ε)

335 nm (3.5 ꢁ 10⁵). CD (CHCl₃, 5 ꢁ 10^ꢀ6M) λ (Δε) 297 nm

(ꢀ97), 334 nm (97), 388 nm (ꢀ214). IR (KBr) 2924, 2146, 1248 cm^ꢀ1

.

Anal. (C₁₉₀H₁₈₄S₄Si₂) Calcd: C, 86.05; H, 6.99. Found: C, 85.81; H,

6.93. ¹H NMR (400 MHz, CDCl₃) δ 0.39 (18H, s), 0.85 (12H, t, J = 7.2

Hz), 1.22ꢀ1.38 (48H, m), 1.46ꢀ1.54 (8H, m), 1.72ꢀ1.80 (8H, m),

1.93 (6H, s), 1.94 (6H, s), 1.98 (18H, s), 3.06 (4H, t, J = 7.2 Hz), 3.07

(4H, t, J = 7.2 Hz), 7.43ꢀ7.52 (10H, m), 7.63ꢀ7.75 (18H, m) 7.83 (2H, t,

J = 1.6 Hz), 7.85 (2H, t, J = 1.6 Hz), 8.02 (2H, s), 8.06 (2H, s), 8.11

(6H, s), 8.43 (2H, d, J = 7.2 Hz), 8.50ꢀ8.57 (8H, m). ¹³C NMR (100

MHz, CDCl₃) δ 0.11, 14.1, 22.7, 23.1, 23.18, 23.23, 28.9, 29.0, 29.2, 29.3,

29.5, 29.6, 31.9, 33.4, 88.7, 93.4, 93.5, 100.1, 103.1, 119.9, 120.0, 120.3,

123.57, 123.64, 124.3, 126.6, 126.7, 126.9, 127.0, 129.1, 129.2, 129.3,

Deprotected (P)-Trimer with Decylthio Side Chains, (P)-S-3H. The

compound (266 mg, 189 mmol, 97%) was prepared from (P)-S-3 (302 mg,

0.195 mmol) as a yellow solid. Mp 123ꢀ125 °C (chloroformꢀmethanol).

[R]²⁷ꢀ670 (c 0.10, CHCl₃). MALDI-TOF MS m/z calcd for

D

12

C

¹³CH₉₂S₂: 1405.7. Found: 1406.4. IR (KBr) 3290, 2924 cm^ꢀ1. Anal.

103

(C₁₀₄H₉₂S₂) Calcd: C, 88.84; H, 6.60. Found: C, 88.67; H, 6.49. ¹H NMR

(400 MHz, CDCl₃) δ 0.86 (6H, t, J = 7.2 Hz), 1.22ꢀ1.38 (24H, m),

1.46ꢀ1.53 (4H, m), 1.75 (4H, quint, J=7.2 Hz), 1.94 (12H, s), 1.98 (6H, s),

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129.7, 129.9, 130.9, 130.97, 131.00, 131.1, 131.2, 131.8, 132.1, 132.2,

132.3, 136.7, 136.86, 136.91, 138.5, 138.6.

0.0145 mmol), cuprous iodide (33.2 mg, 0.174 mmol), tris(2,4,6-

trimethylphenyl)phosphine (33.9 mg, 0.0872 mmol), triphenylpho-

sphine (22.9 mg, 0.0872 mmol), tetrabutylammonium iodide (429

mg, 1.16 mmol), triethylamine (0.26 mL), N,N-dimethylformamide

(1.3 mL), and tetrahydrofuran (1.0 mL) was freeze-evacuated three

times in flask A. In flask B, a solution of (P)-F-2H³⁸(80.0 mg, 0.0727

mmol) in tetrahydrofuran (2.9 mL) was freeze-evacuated three times,

and the mixture was slowly added to flask A. The mixture was stirred at

45 °C for 2 h. The reaction was quenched by adding saturated aqueous

ammonium chloride, and the organic materials were extracted with

toluene three times. The combined organic layer was washed with water

and brine and dried over magnesium sulfate. The solvents were

evaporated under reduced pressure, and separation by silica gel chro-

matography and recycling GPC gave (P)-DF-4 as a yellow solid (153

Deprotected (P)-Pentamer with Decylthio Side Chains, (P)-S-5H.

The compound (157 mg, 0.0626 mmol, 92%) was prepared from (P)-S-

5 (181 mg, 0.0682 mmol) as a yellow solid. Mp 133ꢀ135 °C

(chloroformꢀmethanol). [R]²⁷ꢀ595 (c 0.10, CHCl₃). MALDI-

12

TOF MS m/z calcd for

C

182

¹³^DC₂H₁₆₈S₄: 2507.2. Found: 2506.7. IR

(KBr) 3290, 2922 cm^ꢀ1. Anal. (C₁₈₄H₁₆₈S₄) Calcd: C, 88.13; H, 6.75.

Found: C, 87.85; H, 6.92. ¹H NMR (400 MHz, CDCl₃) δ 0.85 (12H, t,

J = 7.2 Hz), 1.20ꢀ1.40 (48H, m), 1.46ꢀ1.58 (8H, m), 1.72ꢀ1.80 (8H,

m), 1.95 (12H, s), 1.96ꢀ2.00 (18H, m), 3.06 (4H, t, J = 7.2 Hz), 3.07

(4H, t, J = 7.2 Hz), 3.56 (2H, s), 7.44ꢀ7.52 (10H, m), 7.63ꢀ7.76 (18H,

m), 7.83 (2H, t, J = 1.2 Hz), 7.85 (2H, t, J = 1.2 Hz), 8.06 (2H, s), 8.08

(2H, s), 8.12 (4H, s), 8.13 (2H, s), 8.44 (2H, d, J = 8.0 Hz), 8.51ꢀ8.57

(8H, m). ¹³C NMR (100 MHz, CDCl₃) δ 14.1, 22.7, 23.18, 23.23, 28.9,

29.0, 29.2, 29.3, 29.5, 29.6, 31.9, 33.4, 81.8, 82.4, 88.7, 88.8, 93.5, 119.3,

119.98, 120.00, 123.5, 123.61, 123.64, 124.3, 126.66, 126.69, 126.90,

126.94, 129.17, 129.21, 129.24, 129.6, 129.7, 130.4, 130.8, 130.88,

130.93, 131.0, 131.1, 131.2, 131.8, 132.2, 132.3, 136.8, 136.9, 138.6.

(P)-Hexamer with Decylthio Side Chains, (P)-S-6. The compound

(16.2 mg, 0.00506 mmol, 65%) was prepared from (P)-S-4H (15.2 mg,

0.0078 mmol) and (P)-S-1 (12.0 mg, 0.0156 mmol) as a yellow solid.

mg, 0.0646 mmol, 89%). Mp 228ꢀ230 °C (tolueneꢀmethanol). [R]²²

D

ꢀ473 (c 0.10, CHCl₃). MALDI-TOF MS m/z calcd for

12

C

149

¹³CH₁₂₅F₁₇O₄Si₂: 2369.9. Found: 2370.3. UVꢀvis (CHCl_3,

5 ꢁ 10^ꢀ6M) λ_max(ε) 336 nm (2.8 ꢁ 10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6

M) λ (Δε) 297 nm (ꢀ54), 333 nm (89), 387 nm (ꢀ175). IR (KBr)

2924, 2148, 1724, 1240, 1207 cm^ꢀ1. Anal. (C₁₅₀H₁₂₅F₁₇O₄Si₂) Calcd:

C, 75.99; H, 5.31; F, 13.62. Found: C, 75.77; H, 5.48; F, 13.58. ¹H NMR

(600 MHz, CDCl₃) δ 0.39 (18H, s), 0.86 (6H, t, J = 6.6 Hz), 1.26ꢀ1.42

(24H, m), 1.50 (4H, quin, J = 7.2 Hz), 1.85 (4H, quin, J = 7.2 Hz), 1.93

(6H, s), 1.95 (6H, s), 2.00 (12H, s), 4.42 (4H, t, J = 6.6 Hz), 7.44 (2H, d,

J = 7.2 Hz), 7.47 (2H, d, J = 7.2 Hz), 7.50ꢀ7.52 (4H, m), 7.65 (2H, dd,

J = 7.2 Hz), 7.70ꢀ7.75 (6H, m), 7.92 (2H, s), 8.00 (2H, s), 8.05 (2H, s),

8.08 (2H, s), 8.09 (2H, s), 8.18 (2H, s), 8.22 (1H, s), 8.35 (2H, s), 8.36

(2H, s), 8.43 (2H, d, J = 7.8 Hz), 8.53ꢀ8.56 (6H, m). ¹³C NMR (150

MHz, CDCl₃) δ 0.12, 14.1, 22.7, 23.1, 23.17, 23.23, 26.1, 28.8, 29.31,

29.33, 29.6, 31.9, 65.8, 89.3, 89.4, 90.2, 92.3, 92.9, 93.1, 100.2, 103.1,

119.5, 119.7, 120.0, 120.4, 123.5, 123.6, 123.7, 124.3, 124.4, 124.9, 126.7,

126.9, 127.0, 127.108, 127.12, 129.1, 129.2, 129.36, 129.37, 129.5, 129.8,

129.9, 130.1, 130.9, 130.98, 131.02, 131.5, 132.1, 132.3, 132.38, 132.40,

136.8, 136.9, 136.97, 137.02, 137.8, 138.3, 165.4. ¹⁹F NMR (565 MHz,

CDCl₃) δ ꢀ127.4 (2F, s, br), ꢀ124.0 (2F, s, br), ꢀ123.1 (2F, s, br),

ꢀ123.0 (2F, s, br), ꢀ122.6 (2F, s, br), ꢀ122.4 (2F, s, br), ꢀ122.3 (2F, t,

J = 13.3 Hz), ꢀ82.1 (3F, t, J = 9.9 Hz).

Mp 148ꢀ150 °C (chloroformꢀmethanol). [R]²⁶ꢀ624 (c 0.10,

D

12

CHCl₃). MALDI-TOF MS m/z calcd for

C

¹³C₂H₂₂₂S₅Si₂:

228

3201.6. Found: 3201.9. UVꢀvis (CHCl₃, 5 ꢁ 10^ꢀ6M) λ_max(ε)

336 nm (4.5 ꢁ 10⁵). CD (CHCl₃, 5 ꢁ 10^ꢀ6M) λ (Δε) 298 nm

(ꢀ132), 334 nm (95), 388 nm (ꢀ250). IR (KBr) 2922, 2146,

1248 cm^ꢀ1. Anal. (C₂₃₀H₂₂₂S₅Si₂) Calcd: C, 86.25; H, 6.99. Found:

C, 86.48; H, 7.07. ¹H NMR (400 MHz, CDCl₃) δ 0.38 (18H, s), 0.85

(15H, t, J = 7.2 Hz), 1.22ꢀ1.38 (60H, m), 1.46ꢀ1.55 (10H, m),

1.72ꢀ1.80 (10H, m), 1.93 (6H, s), 1.94 (6H, s), 1.98 (24H, s),

3.04ꢀ3.09 (10H, m), 7.43ꢀ7.52 (12H, m), 7.63ꢀ7.75 (22H, m), 7.83

(2H, t, J = 1.6 Hz), 7.84ꢀ7.86 (3H, m), 8.02 (2H, s), 8.05 (2H, s),

8.09ꢀ8.13 (8H, m), 8.42 (2H, d, J = 7.6 Hz), 8.50ꢀ8.56 (10H, m).

¹³C NMR (100 MHz, CDCl₃) δ 0.11, 14.1, 22.7, 23.16, 23.19, 23.24,

28.9, 29.0, 29.2, 29.3, 29.5, 29.6, 31.9, 33.4, 88.7, 93.4, 93.5, 100.1, 103.1,

119.8, 120.0, 120.2, 123.57, 123.64, 124.3, 126.5, 126.7, 126.9, 127.0,

129.1, 129.2, 129.3, 129.7, 129.9, 130.9, 131.0, 131.1, 131.8, 132.1, 132.2,

132.3, 136.7, 136.86, 136.91, 138.6.

Deprotected (P)-Tetramer with Alternating Perfluorooctyl Side

Chains and Decyloxycarbonyl Side Chains, (P)-DF-4H (Typical Proce-

dure for Desilylation of (P)-DF-n). To a solution of (P)-DF-4 (150 mg,

0.0634 mmol) in tetrahydrofuran (1.8 mL) was added 1.0 M tetra-

butylammonium fluoride in tetrahydrofuran (0.16 mL, 0.16 mmol) at

0 °C. After 30 min of stirring at the temperature, the reaction was

quenched by adding saturated aqueous ammonium chloride. The

organic materials were extracted with toluene. The organic layer was

washed with water and brine and dried over magnesium sulfate. The

solvents were evaporated under reduced pressure, and silica gel chro-

matography gave (P)-DF-4H as a yellow solid (141 mg, 0.0634 mmol,

(P)-Heptamer with Decylthio Side Chains, (P)-S-7. The compound

(31.6 mg, 0.00841 mmol, 55%) was prepared from (P)-S-5H (38.6 mg,

0.0154 mmol) and (P)-S-1 (23.8 mg, 0.0308 mmol) as a yellow solid.

Mp 155ꢀ157 °C (chloroformꢀmethanol). [R]²⁶ꢀ574 (c 0.05,

D

12

CHCl₃). MALDI-TOF MS m/z calcd for

C

¹³C₂H₂₆₀S₆Si₂:

268

3751.8. Found: 3751.2. UVꢀvis (CHCl₃, 5 ꢁ 10^ꢀ6M) λ_max(ε)

336 nm (4.9 ꢁ 10⁵). CD (CHCl₃, 5 ꢁ 10^ꢀ6M) λ (Δε) 297 nm

(ꢀ128), 335 nm (119), 388 nm (ꢀ308). IR (KBr) 2924, 2148,

1248 cm^ꢀ1. Anal. (C₂₇₀H₂₆₀S₆Si₂) Calcd: C, 86.40; H, 6.98. Found:

C, 86.74; H, 7.13. ¹H NMR (400 MHz, CDCl₃) δ 0.38 (18H, s), 0.85

(18H, t, J = 7.2 Hz), 1.22ꢀ1.38 (72H, m), 1.46ꢀ1.55 (12H, m),

1.71ꢀ1.80 (12H, m), 1.92 (6H, s), 1.94 (6H, s), 1.97 (30H, s),

3.04ꢀ3.09 (12H, m), 7.43ꢀ7.52 (14H, m), 7.62ꢀ7.75 (26H, m),

7.82 (2H, t, J = 1.6 Hz), 7.83ꢀ7.85 (4H, m), 8.01 (2H, s), 8.04 (2H,

s), 8.08ꢀ8.12 (10H, m), 8.42 (2H, d, J = 8.0 Hz), 8.50ꢀ8.56 (12H, m).

¹³C NMR(100 MHz, CDCl₃) δ 0.11, 14.1, 22.7, 23.15, 23.18, 23.23,

28.9, 29.0, 29.2, 29.3, 29.5, 29.6, 30.9, 31.9, 33.4, 88.7, 93.4, 93.5, 100.1,

103.1, 119.8, 120.0, 120.2, 123.6, 124.3, 126.5, 126.7, 126.87, 126.94,

129.1, 129.16, 129.24, 129.7, 129.9, 130.8, 131.0, 131.1, 131.8, 132.1,

132.2, 132.3, 136.7, 136.85, 136.90, 138.6.

quant). Mp 175 °C, decomp (chloroformꢀmethanol). [R]²³ꢀ523

D

(c 0.10, CHCl₃). MALDI-TOF MS m/z calcd for ¹²C₁₄₃¹³CH₁₀₉F₁₇O₄:

2225.8. Found: 2226.3. UVꢀvis (CHCl_3,5 ꢁ 10^ꢀ6M) λ_max(ε) 333 nm

(2.4 ꢁ 10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 297 nm (ꢀ73), 329 nm

(62), 387 nm (ꢀ166). IR (KBr) 2924, 2207, 1723, 1240, 1207 cm^ꢀ1

.

Anal. (C₁₄₄H₁₀₉F₁₇O₄) Calcd: C, 77.68; H, 4.93; F, 14.51. Found: C,

77.44; H, 5.18; F, 14.24. ¹H NMR (600 MHz, CDCl₃) δ 0.85 (6H, t, J =

7.2 Hz), 1.26ꢀ1.43 (24H, m), 1.50 (4H, quin, J = 7.2 Hz), 1.85 (4H,

quin, J = 7.2 Hz), 1.95 (12H, s), 1.99 (12H, s), 3.56 (2H, s), 4.42 (4H, t,

J = 7.2 Hz), 7.45 (2H, d, J = 7.2 Hz), 7.48 (2H, d, J = 7.2 Hz), 7.50ꢀ7.52

(4H, m), 7.66 (2H, dd, J = 7.8 Hz), 7.70ꢀ7.76 (6H, m), 7.92 (2H, s),

8.04 (2H, s), 8.07 (2H, s), 8.11 (2H, s), 8.12 (2H, s), 8.18 (2H, t, J = 1.5

Hz), 8.22 (1H, s), 8.35 (2H, t, J = 1.5 Hz), 8.36 (2H, t, J = 1.5 Hz), 8.44

(2H, d, J = 7.8 Hz), 8.53 (4H, d, J = 7.8 Hz), 8.55 (2H, d, J = 7.8 Hz). ¹³C

NMR (150 MHz, CDCl₃) δ 14.1, 22.7, 23.17, 23.23, 26.1, 28.7, 29.3,

29.5, 29.6, 31.9, 65.8, 81.8, 82.4, 89.27, 89.31, 90.1, 92.3, 92.9, 93.1,

(P)-Tetramer with Alternating Perfluorooctyl Side Chains and

Decyloxycarbonyl Side Chains, (P)-DF-4 (Typical Procedure for the

Sonogashira Coupling Reaction of (P)-DF-n). Under an argon atmo-

sphere, a mixture of (P)-D-1^39a(114 mg, 0.145 mmol), tris-

(dibenzylideneacetone)dipalladium(0) chloroform adduct (15.1 mg,

4855

dx.doi.org/10.1021/jo200658q |J. Org. Chem. 2011, 76, 4841–4858

The Journal of Organic Chemistry

ARTICLE

119.4, 119.5, 119.8, 119.9, 123.5, 123.55, 123.57, 123.6, 124.29, 124.32,

124.9, 126.8 126.95, 127.00, 127.10, 127.12, 129.0, 129.2, 129.25,

129.35, 129.4, 129.5, 129.8, 130.1, 130.4, 130.86, 130.94, 130.97,

130.99, 131.02, 131.5, 132.1, 132.2, 132.3, 132.4, 136.8, 136.9, 136.98,

137.02, 137.8, 138.3, 165.4. ¹⁹F NMR (565 MHz, CDCl₃) δ ꢀ127.2

(2F, s, br), ꢀ123.8 (2F, s, br), ꢀ123.0 (2F, s, br), ꢀ122.9 (2F, s, br),

ꢀ122.4 (2F, s, br), ꢀ122.2 (2F, s, br), ꢀ122.1 (2F, t, J = 13.6 Hz), ꢀ81.9

(3F, t, J = 9.9 Hz).

(P)-Octamer with Alternating Perfluorooctyl Side Chains and

Decyloxycarbonyl Side Chains, (P)-DF-8. The compound (51.8 mg,

0.0102 mmol, 79%) was prepared from (P)-DF-6H (49.0 mg, 0.0128

mmol) and (P)-D-1 (20.4 mg, 0.0259 mmol) as a yellow solid. Mp >

240 °C (chloroform -methanol). [R]²³ꢀ487 (c 0.10, CHCl₃).

D

12

MALDI-TOF MS m/z calcd for

C

308

H₂₃₅F₅₁O₈Si₂: 5085.7. Found:

5085.9. UVꢀvis (CHCl_3,2.5 ꢁ 10^ꢀ6M) λ_max(ε) 339 nm (5.4 ꢁ 10⁵).

CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 297 nm (ꢀ112), 336 nm (155),

389 nm (ꢀ374). IR (KBr) 2958, 2208, 1724, 1241, 1207 cm^ꢀ1. Anal.

(C₃₀₈H₂₃₅F₅₁O₈Si₂) Calcd: C, 72.69; H, 4.65; F, 19.04. Found: C,

72.37; H, 4.95; F, 18.78. ¹H NMR (600 MHz, CDCl₃) δ 0.38 (18H, s),

0.85 (12H, t, J = 7.2 Hz), 1.26ꢀ1.34 (40H, m), 1.34ꢀ1.47 (8H, m),

1.49ꢀ1.53 (8H, m), 1.82ꢀ1.88 (8H, m), 1.93 (6H, s), 1.94 (6H, s), 1.98

(36H, s), 4.40ꢀ4.43 (8H, m), 7.44 (2H, d, J = 7.2 Hz), 7.47 (2H, d, J =

7.2 Hz), 7.50ꢀ7.51 (12H, m), 7.66 (2H, t, J = 7.8 Hz), 7.70ꢀ7.75 (14H,

m), 7.90ꢀ7.91 (6H, m), 8.01 (2H, s), 8.05 (2H, s), 8.10ꢀ8.11 (12H, m),

8.18 (2H, s), 8.19 (2H, s), 8.22 (3H, s), 8.33ꢀ8.35 (8H, m), 8.42 (2H, d,

J = 7.8 Hz), 8.52ꢀ8.55 (14H, m). ¹³C NMR (150 MHz, CDCl₃) δ 0.11,

14.1, 22.6, 23.1, 23.16, 23.21, 26.1, 28.8, 29.31, 29.33, 29.6, 29.65, 29.70,

31.9, 65.8, 89.28, 89.30, 89.4, 90.2, 92.3, 92.9, 93.1, 100.2, 103.1,

108.3ꢀ118.1 (m, br), 119.5, 119.7, 119.9, 120.4, 123.5, 123.6, 123.66,

123.68, 124.3, 124.4, 124.9, 126.7, 126.9, 127.0, 127.1, 129.1, 129.2,

129.4, 129.5, 129.8, 129.9, 130.0, 130.1, 130.2, 130.9, 131.0, 131.5, 132.1,

132.3, 132.4, 136.8, 136.9, 136.98, 137.02, 137.8, 138.3, 165.4. ¹⁹F NMR

(565 MHz, CDCl₃) δ ꢀ127.3 (6F, s, br), ꢀ123.9 (6F, s, br), ꢀ123.0

(6F, s, br), ꢀ122.9 (6F, s, br), ꢀ122.4 (6F, s, br), ꢀ122.3 (6F, s, br),

ꢀ122.2 (6F, t, J = 13.0 Hz), ꢀ82.1 (9F, t, J = 9.0 Hz).

(P)-Hexamer with Alternating Perfluorooctyl Side Chains and

Decyloxycarbonyl Side Chains, (P)-DF-6. The compound (214 mg,

0.0539 mmol, 80%) was prepared from (P)-DF-4H (150 mg, 0.0674

mmol) and (P)-F-1³⁸(137 mg, 0.135 mmol) as a yellow solid. Mp >

240 °C (chloroformꢀmethanol). [R]²²ꢀ433 (c 0.10, CHCl₃).

D

MALDI-TOF MS m/z calcd for

C

¹³CH₁₅₉F₅₁O₄Si₂: 3962.1.

12

225

Found: 3962.2. UVꢀvis (CHCl_3,2.5 ꢁ 10^ꢀ6M) λ_max(ε) 338 nm

(4.2 ꢁ 10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ (Δε) 297 nm (ꢀ85), 336 nm

(118), 388 nm (ꢀ265). IR (KBr) 2925, 2205, 1726, 1241, 1207 cm^ꢀ1

.

Anal. (C₂₂₆H₁₅₉F₅₁O₄Si₂) Calcd: C, 68.48; H, 4.04; F, 24.44. Found:

C, 68.12; H, 4.26; F, 24.51. ¹H NMR (600 MHz, CDCl₃) δ 0.39 (18H,

s), 0.85 (6H, t, J = 7.2 Hz), 1.26ꢀ1.42 (24H, m), 1.49 (4H, quin, J = 7.2

Hz), 1.85 (4H, quin, J = 7.2 Hz), 1.93 (6H, s), 1.94 (6H, s), 1.99 (24H,

s), 4.42 (4H, t, J = 7.2 Hz), 7.45 (2H, d, J = 7.2 Hz), 7.48 (2H, d, J = 7.2

Hz), 7.50ꢀ7.51 (8H, m), 7.66 (2H, dd, J = 7.8, 7.2 Hz), 7.70ꢀ7.75

(10H, m), 7.90ꢀ7.92 (6H, m), 8.00 (2H, s), 8.06 (2H, s), 8.09 (4H, s),

8.10 (4H, s), 8.19 (2H, s), 8.20 (2H, s), 8.22 (1H, s), 8.36 (4H, s), 8.43

(2H, d, J = 7.8 Hz), 8.53ꢀ8.56 (10H, m). ¹³C NMR (150 MHz,

CDCl₃) δ 0.19, 14.2, 22.8, 23.23, 23.25, 23.32, 26.2, 28.8, 29.4, 29.7,

29.8, 32.0, 65.9, 89.4, 90.22, 90.23, 90.3, 92.3, 92.4, 93.1, 100.4, 103.1,

115.5ꢀ118.4 (m, br), 119.4, 119.6, 120.0, 120.5, 123.5, 123.6, 123.7,

123.8, 124.4, 124.98, 125.00, 125.02, 126.9, 127.06, 127.10, 127.2,

129.3, 129.4, 129.5, 129.46, 129.54, 129.9, 130.2, 130.3, 130.4, 130.9,

131.0, 130.07, 131.10, 131.6, 132.1, 132.2, 132.4, 132.5, 136.9, 137.0,

137.07, 137.10, 137.8, 138.4, 165.5. ¹⁹F NMR (565 MHz, CDCl₃) δ

ꢀ127.3 (6F, s, br), ꢀ123.9 (6F, s, br), ꢀ123.0 (6F, s, br), ꢀ122.9 (6F,

s, br), ꢀ122.5 (6F, s, br), ꢀ122.3 (6F, s, br), ꢀ122.2 (6F, t, J = 14.1

Hz), ꢀ82.1 (9F, t, J = 9.3 Hz).

Deprotected (P)-Octamer with Alternating Perfluorooctyl Side

Chains and Decyloxycarbonyl Side Chains, (P)-DF-8H. The compound

(61.7 mg, 0.0125 mmol, quant) was prepared from (P)-DF-8 (63.5 mg,

0.0125 mmol) as a yellow solid. Mp 212 °C, decomp (chloroformꢀ

methanol). [R]²³_Dꢀ453 (c 0.10, CHCl₃). MALDI-TOF MS m/z calcd

for

C

¹³CH₂₁₉F₅₁O₈:.4942.6. Found: 4942.5. UVꢀvis (CHCl_3,2.5

12

301

ꢁ 10^ꢀ6M) λ_max(ε) 337 nm (4.9 ꢁ 10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ

(Δε) 297 nm (ꢀ133), 337 nm (158), 389 nm (ꢀ374). IR (KBr) 2924,

2207, 1725, 1240, 1207 cm^ꢀ1. Anal. (C₃₀₂H₂₁₉F₅₁O₈) Calcd: C, 73.35;

1

Deprotected (P)-Hexamer with Alternating Perfluorooctyl Side

Chains and Decyloxycarbonyl Side Chains, (P)-DF-6H. The compound

(92.0 mg, 0.0241 mmol, 99%) was prepared from (P)-DF-6 (96.1 mg,

0.0242 mmol) as a yellow solid. Mp 185 °C, decomp (chloroformꢀ

H, 4.46; F, 19.59. Found: C, 73.10; H, 4.72; F, 19.34. H NMR (600

MHz, CDCl₃, observed at 50 °C) δ 0.85 (12H, t, J = 6.6 Hz), 1.26ꢀ1.35

(48H, m), 1.39ꢀ1.42 (8H, m), 1.82ꢀ1.87 (8H, m), 1.95 (12H, s), 1.98

(36H, s), 3.53 (2H, s), 4.40ꢀ4.43 (8H, m), 7.44 (2H, d, J = 6.6 Hz),

7.46ꢀ7.50 (14H, m), 7.64 (2H, d, J = 7.2 Hz), 7.69ꢀ7.72 (14H, m), 7.90

(6H, s), 8.03 (2H, s), 8.06 (2H, s), 8.10ꢀ8.11 (12H, m), 8.16 (2H, s),

8.18 (2H, s), 8.21 (3H, s), 8.32 (2H, s), 8.35 (6H, m), 8.43 (2H, d, J = 7.8

Hz), 8.50ꢀ8.55 (14H, m). ¹³C NMR (150 MHz, CDCl₃, observed at

50 °C) δ 15.4, 26.6, 33.5, 33.89, 33.92, 36.3, 38.5, 38.8, 38.9, 39.1, 40.9,

68.1, 80.9, 81.3, 86.92, 86.94, 87.6, 89.3, 89.8, 89.9, 95.4, 111.0, 111.1,

111.3, 111.5, 114.2, 114.3, 114.4, 114.9, 115.4, 116.9, 116.98, 117.02,

117.10, 117.12, 118.77, 118.81, 118.9, 118.98, 119.01, 119.3, 119.5,

119.7, 119.8, 120.2, 120.3, 120.8, 121.20, 121.24, 121.3, 121.37, 121.41,

124.9, 125.0, 125.05, 125.08, 125.6, 126.0, 147.7. ¹⁹F NMR (565 MHz,

CDCl₃) δ ꢀ127.3 (6F, s, br), ꢀ123.9 (6F, s, br), ꢀ123.1 (6F, s, br),

ꢀ122.9 (6F, s, br), ꢀ122.5 (6F, s, br), ꢀ122.3 (6F, s, br), ꢀ112.2 (6F, s,

br), ꢀ82.0 (9F, t, J = 9.6 Hz).

methanol). [R]²³_Dꢀ437 (c 0.10, CHCl₃). MALDI-TOF MS m/z calcd

12

for

C

218

¹³C2H₁₄₃F₅₁O₄: 3819.0. Found: 3818.7. UVꢀvis (CHCl_3,2.5

ꢁ 10^ꢀ6M) λ_max(ε) 336 nm (3.8 ꢁ 10⁵). CD (CHCl_3,5 ꢁ 10^ꢀ6M) λ

(Δε) 296 nm (ꢀ104), 332 nm (88), 389 nm (ꢀ259). IR (KBr) 2925,

2207, 1725, 1241, 1208 cm^ꢀ1. Anal. (C₂₂₀H₁₄₃F₅₁O₄) Calcd: C, 69.18;

1

H, 3.77; F, 25.37. Found: C, 68.86; H, 4.17; F, 25.29. H NMR (600

MHz, CDCl₃, observed at 40 °C) δ 0.85 (6H, t, J = 7.2 Hz), 1.26ꢀ1.36

(24H, m), 1.41 (4H, quin, J = 7.2 Hz), 1.85 (4H, quin, J = 7.2 Hz), 1.95

(12H, s), 1.99 (24H, s), 3.54 (2H, s), 4.42 (4H, t, J = 7.2 Hz), 7.45 (2H,

d, J = 7.2 Hz), 7.48 (2H, d, J = 7.2 Hz), 7.49ꢀ7.51 (8H, m), 7.65 (2H, dd,

J = 7.8 Hz), 7.70ꢀ7.74 (10H, m), 7.89 (2H, s), 7.90 (2H, s), 7.91(2H, s),

8.04 (2H, s), 8.08 (2H, s), 8.11 (4H, m), 8.12 (4H, m), 8.19 (4H, s), 8.22

(1H, s), 8.35ꢀ8.36 (4H, m), 8.44 (2H, d, J = 7.8 Hz), 8.50ꢀ8.56 (10H,

m). ¹³C NMR (150 MHz, CDCl₃, observed at 40 °C) δ 14.0, 22.7, 23.1,

23.2, 26.1, 28.8, 29.31, 29.34, 29.6, 31.9, 65.9, 81.8, 82.4, 89.4, 90.2, 92.3,

92.4, 93.1, 105.0ꢀ119.0 (m, br), 119.5, 119.56, 119.59, 120.0, 123.5,

123.55, 123.62, 123.7, 124.4, 125.0, 127.03, 127.05, 127.07, 127.09,

127.12, 127.2, 129.25, 129.33, 129.36, 129.38, 129.4, 129.5, 129.9,

130.08, 130.14, 130.3, 130.4, 130.5, 130.87, 130.90, 131.0, 131.05,

131.08, 131.7, 132.1, 132.2, 132.4, 132.46, 132.52, 136.9, 137.0, 137.1,

137.8, 138.3, 165.4. ¹⁹F NMR (565 MHz, CDCl₃, observed at 40 °C) δ

ꢀ127.1 (6F, s, br), ꢀ123.7 (6F, s, br), ꢀ122.9 (6F, s, br), ꢀ122.7 (6F, s,

br), ꢀ122.3 (6F, s, br), ꢀ122.1 (6F, s, br), ꢀ122.0 (6F, t, J = 12.7 Hz),

ꢀ81.9 (9F, t, J = 8.5 Hz).

(P)-Decamer with Alternating Perfluorooctyl Side Chains and

Decyloxycarbonyl Side Chains, (P)-DF-10. The compound (17.4 mg,

0.00260 mmol, 40%) was prepared from (P)-DF-8H (32.0 mg, 0.00647

mmol) and (P)-F-1 (13.2 mg, 0.0129 mmol) as a yellow solid. Mp

>240 °C (chloroformꢀmethanol). [R]²³ꢀ394 (c 0.10, CHCl₃).

D

MALDI-TOF MS m/z calcd for C₃₈₄H₂₆₉F₈₅O₈Si₂: 6677.9. Found:

6678.4. UVꢀvis (CHCl_3,2.5 ꢁ 10^ꢀ6M) λ_max(ε) 338 nm (6.9 ꢁ 10⁵).

CD (CHCl_3,2.5 ꢁ 10^ꢀ6M) λ (Δε) 296 nm (ꢀ147), 338 nm (158),

390 nm (ꢀ466). IR (KBr) 2924, 2208, 1725, 1241, 1208 cm^ꢀ1. Anal.

(C₃₈₄H₂₆₉F₈₅O₈Si₂) Calcd: C, 69.02; H, 4.06; F, 24.17. Found: C,

1

68.68; H, 4.37; F, 23.92. H NMR (600 MHz, CDCl₃, observed at

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The Journal of Organic Chemistry

ARTICLE

50 °C) δ 0.38 (18H, s), 0.85 (12H, t, J = 6.6 Hz), 1.26ꢀ1.34 (48H, m),

1.38ꢀ1.43 (8H, m), 1.82ꢀ1.87 (8H, m), 1.93 (6H, s), 1.94 (6H, s),

1.98ꢀ1.99 (48H, s), 4.42 (8H, t, J = 6.6 Hz), 7.44 (2H, d, J = 7.2 Hz),

7.46ꢀ7.50 (18H, m), 7.65 (2H, t, J = 7.2 Hz), 7.69ꢀ7.73 (18H, m),

7.89ꢀ7.90 (10H, m), 8.00 (2H, s), 8.07 (2H, s), 8.11ꢀ8.13 (16H, m),

8.18ꢀ8.21 (9H, m), 8.34ꢀ8.35 (6H, m), 8.35 (2H, s), 8.42 (2H, d, J =

7.8 Hz), 8.49ꢀ8.55 (18H, m). ¹³C NMR (150 MHz, CDCl₃, observed at

55 °C) δ 0.12, 14.0, 22.6, 22.7, 23.0, 23.06, 23.08, 23.13, 23.9, 26.1, 28.8,

29.0, 29.29, 29.34, 29.4, 29.6, 29.67, 29.71, 30.5, 31.9, 32.0, 36.4, 39.0,

65.9, 89.4, 90.28, 90.30, 92.4, 93.2, 100.0, 103.2, 119.5, 119.7, 120.1,

120.6, 123.5, 123.6, 123.73, 123.74, 123.75, 123.81, 124.5, 125.08,

125.10, 125.13, 126.9, 127.0, 127.13, 127.14, 127.16, 127.17, 127.19,

129.2, 129.28, 129.29, 129.37, 129.39, 129.45, 129.47, 129.48, 129.87,

129.88, 130.17, 130.18, 130.19, 131.05, 131.12, 131.13, 131.14, 131.8,

132.2, 132.3, 132.46, 132.48, 132.50, 132.6, 136.6, 136.7, 136.8, 136.9,

137.02, 137.05, 137.07, 137.10, 137.13, 137.76, 137.78, 137.80, 138.3,

165.4. ¹⁹F NMR (565 MHz, CDCl₃, observed at 40 °C) δ ꢀ127.2 (10F,

s, br), ꢀ123.8 (10F, s, br), ꢀ123.0 (10F, s, br), ꢀ122.9 (10F, s, br),

ꢀ122.4 (10F, s, br), ꢀ122.2 (10F, s, br), ꢀ112.1 (10F, s, br), ꢀ82.0

(15F, t, J = 8.8 Hz).

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’ ASSOCIATED CONTENT

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b

7, and (P)-DF-8, VPO results of (P)-DF-8, and copies of ¹H and

¹³C NMR spectra of all new compounds. This material is

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Corresponding Author

*E-mail: yama@mail.pharm.tohoku.ac.jp.

’ ACKNOWLEDGMENT

The authors thank the Japan Society for the Promotion of

Science (JSPS) for ﬁnancial support to the GCOE program and

the WPI initiative. A fellowship to N.S. from JSPS for young

Japanese scientists is also gratefully acknowledged.

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