European Journal of Organic Chemistry
10.1002/ejoc.201701040
COMMUNICATION
–
Their log β (10.0-10.3) obtained in the presence of F were in the
same range as those determined for 1a, 2a and 3a.
TLC: R
f
(CH
2
Cl
2
/Petrol Ether, 2:3) = 0.70; M.p. 163.4°C; IR (KBr) ν =
–
1 1
3
333, 1552, 1469, 1380, 1277, 1168, 1130, 1110, 876, 761, 680 cm ; H
NMR (200 MHz, DMSO-d ): δ (ppm) = 11.68 (s, 1H, NH), 8.66 (s, 2H),
7.98 (s, 1H), 7.85 (s, 1H), 7.65 (m, 1H), 7.57 (m, 1H), 7.36 (m, 2H), 3.99
6
Noteworthly, (thio)amido-indenes 3a–b offered possible
alternatives to the corresponding (thio)amido-indoles 1–2, for a
fine tuning in Keq in both anion recognition and proton exchange.
1
3
(s, 2H); C NMR (75 MHz, DMSO-d
6
): δ (ppm) = 192.2, 147.3, 144.5,
C,F = 33.0 Hz), 127.5, 127.1, 124.2 (bs),
JC,F = 270.8 Hz), 118.8 (bs), 40.4; HRMS (EI): m/z
2
1
1
42.7, 141.4, 134.7, 130.2 (q, J
1
23.6, 123.2 (q,
Compared to other (thio)-amide based receptors that
possess additional binding groups and/or a different geometry
calculated for C18H11F6NS [M]: 387.0516; found 387.0518
[
18]
+
–
(
bended, macrocycle), HBD compounds 1–3 can be classified
Crystallographic Data: CCDC 1547942-1547944 ([(1a – 0.5 H )
2
.PF
6
[
1],[2]
+
+
–
+
+
as anion receptors
for the less basic species and are
.(nBu N ) ] , [1b.n-Bu N .PhCO ] and [(1b – H ).n-Bu N ] respectively)
4 2 2 4 2 2 4 2
–
contain the supplementary crystallographic data for this communication.
deprotonated by most basic ones (at least F ), as seen for some
[
6],[19]
squaramides and thioureas
.
UV-Visible Titrations: all solutions were freshly prepared. Equilibrium
constants (Keq
4
) between hosts 1–3 and guests (n-Bu NX) were
determined using titrations monitored by UV-Visible (host signals) in
Conclusions
–5
acetonitrile. A solution (2.5 mL) of host (2.5 × 10 M) was introduced in a
quartz cuvette at 20°C. Increasing aliquots (20 µL) of guest stock solution
–
3
–2
We reported the X-ray structure of a supramolecular complex at
the half-equivalence involving two Hydrogen-bond donor
compounds that sandwiched an anion, then merging classical
properties between anions and HBD receptors, i.e. acid-base
reaction and anion binding. This evidence may pave the way for
the development of novel molecular receptors. We also
demonstrated that unsophisticated (thio)amido- indoles and
indenes 1–3 exhibited high equilibria constants in the range of
3
(5×10 –10 M in CH CN) were successively added until the final total
volume reached 2.8 ml at maximum. At each addition, the same aliquot
was added to the reference tank (acetonitrile, 2.5 mL) The titration data
(
Dε versus guest concentration) were fitted using the nonlinear curve-
fitting procedure with a (1:1) or (1:2) binding equation using Letagrop
[
16]
program
.
+
3
+6
–1
Acknowledgements
1
0
to 10
M
in the presence of different anions.
The authors grateful acknowledge the Université de Bordeaux
and CNRS for support. Cybille Rossy is thanked for NMR
experiments.
Experimental Section
[
10]
[10]
[20]
Compounds 1a–b,
2a–b
and indene-2-carboxylic acid
were
synthesized according to the literature procedure.
Keywords: Anion • Hydrogen-bonding • Half-equivalence •
amido-indole • Supramolecular
N-(3,5-bis(trifluoromethyl)phenyl-1H-indene-2-carboxamide (3a): to a
suspension of indene-2-carboxylic acid (480 mg, mmol) in
3
[
[
1]
2]
N. H. Evans, P. D. Beer, Angew. Chem. Int. Ed. 2014, 53, 11716-11754.
(a) P. D. Beer, P. A. Gale, Angew. Chem. Int. Ed. 2001, 40, 486-516;
dichloromethane (10 mL) was added dropwise thionyl chloride (2.2 mL, 3
mmol). The suspension was refluxed for 1h and concentrated. The
residue was dissolved in dichloromethane (10 mL) and a solution of 3,5-
bis-(trifluoromethyl)aniline (573 mg, 2.5 mmol) and diisopropylethylamine
(
b) T. Gunnlaugsson, M. Glynn, G. M. Tocci, P. E. Kruger, F. M. Pfeffer,
Coord. Chem. Rev. 2006, 250, 3094-3117; (c) V. Amendola, L.
Fabbrizzi, L. Mosca, Chem. Soc. Rev. 2010, 39, 3889-3915; (d) S.
Kubik, Chem. Soc. Rev. 2010, 39, 3648-3663; (e) V. Blazk Bregovic, N.
Basaric, K. Mlinaric-Majerski, Coord. Chem. Rev. 2015, 295, 80-124; (f)
M. J. Langton, C. J. Serpell, P. D. Beer, Angew. Chem. Int. Ed. 2016,
(
646 mg, 5 mmol) in dichloromethane (5 mL) was added dropwise. The
reaction mixture was heated at reflux for 14h. The solution was diluted
using dichloromethane (20 mL) and successively washed with
saturated sodium bicarbonate solution (2 20 mL), saturated
a
×
a
5
5, 1974-1987.
ammonium chloride solution (2 × 10 mL) and water (2 × 10 mL). The
organic phase was dried over magnsium sulfate and concentrated in
vacuum. The solid residue was purified by column chromatography on
[
[
[
3]
4]
5]
(a) P. R. Brotherhood, A. P. Davis, Chem. Soc. Rev. 2010, 39, 3633-
3
647. (b) J. T. Davis, O. Okunola, R.Quesada, Chem. Soc. Rev. 2010,
9, 3843-3862. (c) P. A. Gale, Acc. Chem. Res. 2011, 44, 216-226. (d)
3
silica gel (eluent: CH
2
Cl
780 mg, 84%); TLC: R
KBr) ν = 3294, 1643 (s), 1557, 1526, 1469, 1444, 1382, 1273, 1204,
2
/Petrol Ether, 1:1) to provide 3a as a white solid
P. A. Gale, R. Perez-Tomas, R.Quesada, Acc. Chem. Res. 2013, 46,
801-2813.
(a) H. Juwarker, K.-S. Jeong, Chem. Soc. Rev. 2010, 39, 3664-3674.
b) P. D. Beer, M. R. Sambrook, D. Curiel, Chem. Commun. 2006,
(
f
(CH Cl /Petrol Ether, 1:1) = 0.63; M.p. 168°C; IR
2
2
2
(
–
1 1
1
=
7
166, 1109, 890, 764, 682 cm
6
; H NMR (300 MHz, DMSO-d ): δ (ppm)
(
10.51 (s, 1H, NH), 8.49 (s, 2H), 7.88 (s, 1H), 7.73 (s, 1H), 7.61 (m, 1H),
2
2
2
105-2117. (c) S. Vickers, P.D. Beer, Chem. Soc. Rev. 2007, 36, 211-
25. (d) A. Caballero, F. Zapata, P. D. Beer, Coord. Chem. Rev. 2013,
57, 2434-2455.
4
13
.56 (m, 1H), 7.34 (m, 2H), 3.78 (d,
JH,H = 2.1 Hz, 2H); C NMR (75
MHz, DMSO-d
6
): δ (ppm) = 163.4, 144.1, 142.5, 141.1, 140.8, 137.4,
2
1
1
1
30.6 (q, JC,F = 33.5 Hz), 127.2, 126.8, 124.3, 123.3 (q, JC,F = 274.1 Hz),
23.2, 119.3 (bs), 115.9 (bs), 38.2; HRMS (EI): m/z calculated for
NO [M]: 371.0745; found 371.0747
B. List, Angew. Chem. Int. Ed. 2013, 52, 518-533. (b) Z. Zhang, P. R.
Schreiner, Chem. Soc. Rev. 2009, 38, 1187-1198. (c) I. T. Raheem,
P.S. Thiara, E. A. Peterson, E. N. Jacobsen, J. Am. Chem. Soc. 2007,
18 11 6
C H F
1
29, 13404-13405. (d) C. K. De, E. G. Klauber, D. Seidel, J. Am. Chem.
N-(3,5-bis(trifluoromethyl)phenyl-1H-indene-2-carbothioamide (3b):
a solution of 3a (1 mmol) and the Lawesson's reagent (1 mmol) in dry
toluene (15 mmol) was refluxed for 16h. After concentration in vacuo, the
residue was purified by column chromatography on silica gel (eluent:
Soc. 2009, 131, 17060-17061. (e) H. Zhang, S. Lin, E. N. Jacobsen, J.
Am. Chem. Soc. 2014, 136, 16485-16488.
[6]
(a) M. Vazquez, L. Fabbrizzi, A. Taglietti, R. M. Pedrido, A. M.
Gonzalez-Noya, M. R. Bermejo, Angew. Chem. Int. Ed. 2004, 43, 1962-
1965. (b) M. Boiocchi, L. Del Boca, D. Esteban Gomez, L. Fabbrizzi, M.
2 2
CH Cl /Petrol Ether, 2:3) to get 3b as an orange solid (356 mg, 92%);
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