First experimental evidence of an intramolecular H bond between aliphatic Cl and aromatic C-H

Article abstract of DOI:10.1021/cg201219g

The first example of an intramolecular H bond between aliphatic Cl and aromatic C-H was observed in the crystal of C₂-symmetric (4R,5R)-4,5-bis(diphenylchloromethyl)-1,3,2-dioxathiolane 2-oxide. In this case one Cl atom is engaged in H-bonding

Full text of DOI:10.1021/cg201219g

COMMUNICATION
pubs.acs.org/crystal
First Experimental Evidence of an Intramolecular H Bond between
Aliphatic Cl and Aromatic CÀH
||
Xiaoyun Hu,†,‡ Zixing Shan,*,† and Vadim A. Soloshonok§,
†Department of Chemistry, Wuhan University, Wuhan 430072, China
‡College of Chemistry and Materials, South-central University for Nationalities, Wuhan 430073, China
§Department of Organic Chemistry I, Faculty of Chemistry, University of the Basque Country UPV/EHU, 20018 San Sebastian, Spain
IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
S Supporting Information
b
ABSTRACT: The first example of an intramolecular H bond between
aliphatic Cl and aromatic CÀH was observed in the crystal of C2-symmetric
(4R,5R)-4,5-bis(diphenylchloromethyl)-1,3,2-dioxathiolane 2-oxide. In this
case one Cl atom is engaged in H-bonding with two ortho-CÀH groups in
ꢀ
the axial and equatorial phenyl planes, with the recorded distances of 2.562 Å
ꢀ
and 2.804 Å, respectively. The observed angle for CaÀHÀCl is 108.41° and
that for CqÀHÀCl is 96.53°.
nderstanding the nature of chemical bonding is of the most
fundamental importance in chemistry.1 Our ability to
Since their seminal work, a great number of compounds posses-
U
sing CÀH E (E = O, N, S, F, Cl, Br, I, etc.) H-bonds have
3 3 3
describe and predict the reactivity and chemical and physical
properties of molecules and chemical compounds is a derivative
of what we know about chemical bonding. Therefore, any new
data, refining and widening the frontiers of our knowledge of
chemical bonding, are of paramount importance in the theoret-
ical and practical aspects of current science of chemistry.2
The hydrogen bond, a bond bridging two electronegative atoms
by a hydrogen atom, plays a very important role in biology,3
material science,4 and chemistry.5 In the past nearly 80 years,
investigations of hydrogen bonds have yielded a great wealth of
knowledge about various types and forms of hydrogen bonding
phenomena.6 However, the most studied examples dealt with the
been discovered. One of the rare examples is the CÀH Cl
3 3 3
H-bond, for which most of the reported examples (intra- and
intermolecular) involve anionic ClÀ.10 Examples of the H-bond
between CÀH and covalent Cl are even rarer, and all involve Cl
bonded to an aromatic ring.11 In these cases, the corresponding
H-bond is facilitated by the flat geometry of the aromatic ring and
the unshielded steric position of the Cl atom. Thus, to the best of
our knowledge, a particular case of a CÀH Cl H-bond in-
3 3 3
volving an aliphatic Cl atom has never been reported.
In the course of our work on the chemistry of chiral 1,1,4,4-
tetrasubstituted butanetetraol12 and its application for studying
self-disproportionation of enantiomers via achiral chromato-
graphy,13 sublimation,14 as well as heterocomplexation crystal-
lization,15 we designed and synthesized a C2 chiral cyclic sulfite
ester (4R,5R)-4,5-bis(diphenylchloromethyl)-1,3,2-dioxathio-
lane 2-oxide (2) via the reaction of (2R,3R)-1,1,4,4-tetraphenyl-
butanetetraol16 (3) with SOCl2 (Scheme 1), and we found that
selective 2,3-cyclosulfitation of (2R,3R)-3 preferentially occurred
to form (4R,5R)-4,5-bis(diphenylhydroxymethyl)-1,3,2-dioxa-
thiolane 2-oxide (4). Sequentially, the resulting (4R,5R)-4 was
chlorinated step by step to furnish (4R,5R)-2. (4R,5R)-2 was
dissolved in hot ethanol and then slowly cooled to afford single
XÀH Y (X, Y = O, N, S) type of relatively strong H-bonds,
3 3 3
playing a significant role in biology. On the other hand, other
types of rather weak H-bonds,7 involving, for instance, the CÀH
bond as a H-bond donor, have been substantially much less
studied. Thus, the CÀH E type of weak H-bond (E = elec-
3 3 3
tronegative atoms except for carbon), since it was proposed by
Glasstone in 1937,8 is still one of the most long-standing con-
tentions in organic chemistry. Taylor and Kennard most defi-
nitely presented two basic crystallographic characteristics of the
weak CÀH E (E = O, N, Cl) H-bond based on systematic
3 3 3
investigation of neutron diffraction crystal structures in 1982.9 In
particular, the distance between the proton and the acceptor
atom is shorter than the sum of their van der Waals radii, and the
donorÀprotonÀacceptor angle in a H-bond must be at least 90°.
Received: September 16, 2011
Revised:
November 1, 2011
Published: November 10, 2011
r
2011 American Chemical Society
33
dx.doi.org/10.1021/cg201219g Cryst. Growth Des. 2012, 12, 33–36
|

Crystal Growth & Design
COMMUNICATION
Scheme 1. Synthesis of (4R,5R)-2
Figure 3. Intermolecular CÀH O H-bonds in a crystal of (4R,5R)-2.
3 3 3
For clarity, the bond angle of the CÀH O and the H O distance
3 3 3
3 3 3
were separately written.
formation of a CÀHo Cl H-bond,18 and the bond intensity in
3 3 3
the first case is higher. This is the first example of a clear
intramolecular H-bond between the aliphatic chlorine and the
CÀH bond. While the distanceÀangle characteristics9 obtained
for compound (4R,5R)-2 are undoubtedly pointing to the
presence of a CÀH ClÀC hydrogen bond, we decided still
3 3 3
to seek additional noncrystallographic evidence. In particular, in
light of a conclusion made by Thallapally and Nangia19 on a
rather difficult distinction between true CÀH Cl hydrogen
3 3 3
Figure 1. Crystal structure of (4R,5R)-2 with numbering scheme.
bonds and merely van der Waals interactions, based only on
crystal structure analysis, we decided to study the IR spectra of
compound (4R,5R)-2. It is well-known that absorption of a
CÀCl bond in IR spectra is found at a broad region of 800À
600 cmÀ1, and most commonly at 750À700 cm
.
À1 20 In the IR
spectra of compound (4R,5R)-2, there is a strong absorption at
the lower-than-usual wavenumber region of 615 cmÀ1, corre-
sponding to the CÀCl bond. One may agree that this result is in
full agreement with the theoretical prediction, considering that in
the case of the CÀH ClÀC hydrogen bond the charge
3 3 3
density on the Cl atom is decreased as well as the strength of
the CÀCl bond, resulting in IR absorption of the CÀCl bond
shifted toward the low wavenumber region. Thus, the observed
absorption of the CÀCl bond in the IR spectra of compound
(4R,5R)-2 serves as additional, noncrystallographic evidence for
the CÀH ClÀC hydrogen bond. The formation of CÀH Cl
3 3 3
3 3 3
H-bonds would result in weakening of the CÀH bond and stre-
ngthening of the ClÀC bond. Thus, it is estimated that both the
stability of the CÀCl bond as well as the reactivity of the CÀH
bond are increased. This result perhaps can be a helpful guide in
the design of a new type of catalysts for selective activation of
aromatic CÀH bonds.
Figure 2. Intramolecular CÀH Cl and CÀH O weak H bonds in
3 3 3
3 3 3
a crystal of (4R,5R)-2. For clarity, only one set of data were labeled per
weak H bond.
crystals suitable for X-ray crystallographic analysis.17 The crystal
structure of (4R,5R)-2 is shown in Figure 1. The crystallographic
data reveal that there are four molecules of (4R,5R)-2 in a unit
cell. (4R,5R)-2 belongs to a typical orthorhombic system, with
space group C222(1) but possesses several very complicated
intramolecular and intermolecular H-bond networks.
In addition, it was also observed that the distance between
another ortho-CÀH of the equatorial phenyls and the oxygen of
ꢀ
the 1,3,2-dioxathiolane ring is 2.493 Å, with bond angle 108.92°,
indicating the existence of another intramolecular CÀHo
O
3 3 3
(in the five-membered ring) H-bond. The above facts reveal that
the aromatic ortho-CÀH bonds can participate in the formation
of the different types of intramolecular H-bonds.
Figure 2 depicts the intramolecular CÀH Cl and CÀH
O
3 3 3
3 3 3
(the 1,3,2-dioxathiolane ring) H-bonds in the crystal of
(4R,5R)-2. It may be seen from Figure 2 that the distances from
the Cl to ortho-CÀH groups in the axial and equatorial phenyl
Intermolecular CÀH O H-bonds also exist in the crystal of
3 3 3
(4R,5R)-2. As seen in Figure 3, the distance from the oxygen of
the SdO bond in one molecule of (4R,5R)-2 to the meta-C-H in
the equatorial phenyl planes in the adjacent two molecules of
ꢀ
ꢀ
planes are 2.562 Å and 2.804 Å, respectively, with the bond angles
108.41° for CaÀHÀCl and 96.53° for CqÀHÀCl, indicating that
the chlorines at the aliphatic quaternary carbons participate in the
ꢀ
(4R,5R)-2 is 2.59 Å, with a 159.57° angle; meanwhile, the same
distance and angle exist between the meta-CÀH in the equatorial
34
dx.doi.org/10.1021/cg201219g |Cryst. Growth Des. 2012, 12, 33–36

Crystal Growth & Design
COMMUNICATION
Scheme 2. (4R,5R)-2 Was Oxidized into the Corresponding
Sulfate Ester by Air O2
five-membered ring. Therefore, (4R,5R)-2 is a more stable cyclic
sulfite ester than its cyclic sulfite ester analogues, such as
(4R,5R)-4-diphenylchloromethyl-5-diphenylhydroxymethyl-1,3,
2-dioxathiolane 2-oxide and (4R,5R)-4,5-bis(diphenylhydroxy-
methyl)-1,3,2-dioxathiolane 2-oxide as well as 2,3-ketone-pro-
tected chloro-substituted TADDOLs (where the CÀCl bond
was readily broken by MeOH merely by simple crystallization
from MeOH).21 In fact, it has been observed that (4R,5R)-2 does
not undergo ring-opening and cleavage of the CÀCl bond in 2 M
NaOH at room temperature, and it is easily oxidized by the
oxygen in air into the corresponding sulfate ester (Scheme 2).
In summary, a molecule possessing an intramolecular H-bond
between the Cl atom, bonded to an aliphatic carbon, and an
aromatic CÀH has been discovered for the first time in a C2 chiral
cyclic sulfite ester, (4R,5R)-4,5-bis(diphenylchloromethyl)-
1,3,2-dioxathiolane 2-oxide [(4R,5R)-2]. In this molecule, there
Figure 4. Molecular assmbly of crystalline (4R,5R)-2.
also is another type of intramolecular H-bond CÀH O (the
3 3 3
dioxathiolane ring) as well as electrostatic repulsive interactions
between the Cl atoms and the SdO group. Combination of these
intramolecular H-bonds and electrostatic interactions may result
in very unusual reactivity of compound 2, which is currently
under investigation and will be reported in due course.
Figure 5. Electrostatic repulsive interactions in a crystal of (4R,5R)-2.
’ ASSOCIATED CONTENT
phenyl planes in (4R,5R)-2 and the oxygen of the SdO bond in
the adjacent (4R,5R)-2 molecules. It quite agrees with the char-
S
Supporting Information. The preparative procedure,
b
acter of an intermolecular weak H-bond CÀH O (sulfinyl
spectra, and CIF data for (4R,5R)-2. This material is available
3 3 3
group).18 Thus, the (4R,5R)-2 molecules are self-assembling into
an infinite, layered framework along the c axis through inter-
free of charge via the Internet at http://pubs.acs.org.
molecular CÀHm O bonds (Figure 4).
’ AUTHOR INFORMATION
3 3 3
Further examination of the crystallographic data showed that
Corresponding Author
*E-mail: zxshan@whu.edu.cn.
in (4R,5R)-2 the distance between Cl and the oxygen of the SdO
ꢀ
bond is 3.328 Å, and the distances from the sulfur to the Clα and
ꢀ
Cl1α are 3.151 and 3.588 Å, respectively, meaning that there is an
effective electrostatic repulsive interaction between the chlorine
atoms and the atoms of the SdO group. Furthermore, interac-
tion of Clα with the O of the SdO is stronger than that between
the sulfur and either Cl (Figure 5). The electrostatic repulsive
interactions change the space distribution of the substituted
groups and increase the symmetry of the molecule, resulting
also in a change of the bond lengths and bond angles in the ring.
As seen from Figures 1À5, the sulfur atom is located above the
two equatorial phenyl planes and in the opposite direction to
both the perpendicular phenyl planes. Therefore, the steric effect
of the phenyl groups at C(4) and C(5) on the SdO bond is
insignificant. On the other hand, Clα and Cl1α are located above
the two equatorial phenyl planes and, thus, almost symmetrically
arranged on the two sides of the 1,3,2-dioxathiolane ring.
Furthermore, both Cl atoms not only hinder the 1,3,2-dioxathio-
lane ring but also engaged in electrostatic repulsive inter-
actions, making an additional effect on the reactivity of the
’ ACKNOWLEDGMENT
This work was supported by the National Natural Science
Foundation of China (20672083 and 20872115) with financial
support.
’ REFERENCES
(1) (a) Pauling, L. The nature of the chemical bond, 3th ed.; Cornell
University Press: Ithaca, NY, 1980. (b) Zewail, A. H. J. Phys. Chem. A
2000, 104 (24), 5660. (c) Seebach, D. Angew. Chem., Int. Ed. Engl. 1990,
29, 1320. (d) Reed, A. E.; Schleyer, P. v. R. J. Am. Chem. Soc. 1990
112 (4), 1434–1445.
(2) (a) Fischer, R. C.; Power, P. P. Chem. Rev. 2010, 110 (7), 3877.
(b) Mindiola, D. J. Acc. Chem. Res. 2006, 39 (11), 813.(c) Cotton, F. A.;
Murillo, C. A.; Walton, R. A. In Multiple Bonds between Metal Atoms, 3rd ed.;
Cotton, F. A., Murillo, C. A., Walton, R. A., Eds.; 2005; p 1. (d) Burrows,
A. D. Struct. Bonding (Berlin) 2004, 108 55.
35
dx.doi.org/10.1021/cg201219g |Cryst. Growth Des. 2012, 12, 33–36

Crystal Growth & Design
COMMUNICATION
(3) For recent important reviews, see:(a) Ogretir, C. In Advances
in Quantum Chemical Bonding Structures; Putz, M. V., Ed.; 2008;
pp 271À285. (b) Laurence, C.; Berthelot, M. Perspect. Drug Discovery
Des. 2000, 18 (Hydrophobicity and Solvation in Drug Design, Pt. II),
39À60. (c) Flakus, H. T.; Pyzik, A. Chem. Phys. Res. J. 2007, 1 (1), 49–59.
(d) Niimura, N.; Bau, R. Acta Crystallogr., Sect A: Found. Crystallogr.
2008, A64 (1), 12–22. (e) Kojic-Prodic, B.; Molcanov, K. Acta Chim.
Sloven. 2008, 55 (4), 692–708. (f) Vorburger Mielczarek, E. J. Am. Phys.
2006, 74 (5), 375–381. (g) Baglioni, P.; Berti, D. Curr. Opin. Colloid
Interface Sci. 2003, 8 (1), 55–61.
25 (20), 4917. (c) Hu, X. Y.; Shan, Z. X.; Peng, X. T. Tetrahedron:
Asymmetry 2009, 20 (21), 2474. (d) Shan, Z. X.; Hu, X. Y.; Zhou, Y.;
Peng, X. T.; Yi, J. Tetrahedron: Asymmetry 2009, 20 (12), 1445. (e) Shan,
Z. X.; Hu, X. Y.; Zhou, Y.; Peng, X. T.; Li, Z. Helv. Chim. Acta 2010
93 (3), 497.
(13) (a) Soloshonok, V. A.; Berbasov, D. O. J. Fluorine Chem. 2006,
127, 597–603. (b) Soloshonok, V. A.; Berbasov, D. O. Chim. Oggi 2006,
24, 44. (c) Soloshonok, V. A. Angew. Chem., Int. Ed. 2006, 45, 766–769.
(d) Han, J.; Nelson, D. J.; Sorochinsky, A. E.; Soloshonok, V. A. Curr.
Org. Synth. 2011, 8, 310.
(4) For recent important reviews, see:(a) Tal’roze, R. V.; Shatalova,
A. M.; Shandryuk, G. A. Vysokomol. Soedin., Ser. A Ser. B 2009, 51 (3),
489–516.(b) Custelcean, R. Chem. Commun. 2008, (3), 295À307.
(c) Rostro, B. C. Tribol. Lubr. Technol. 2007, 63 (10), 32–40.(d) Dalal,
N. S.; Gunaydin-Sen, O.; Bussmann-Holder, A. Struct. Bonding (Berlin)
2007, 124 (Ferro- and Antiferroelectricity), 23À50. (e) Kharlampieva,
E.; Sukhishvili, S. A. Polym. Rev. 2006, 46 (4), 377À395. (f) Torgova,
S. I.; Strigazzi, A. Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A: Mol. Cryst.
Liq. Cryst. 1999, 336, 229–245.
(5) For recent important reviews, see:(a) Shoji, M.; Hayashi, Y.
In Hydrogen Bonding in Organic Synthesis; Pihko, P. M., Ed.; 2009;
pp 353À371. (b) Nakanishi, W. In Superbases for Organic Synthesis;
Ishikawa, T., Ed.; 2009; pp 273À293. (c) Kohen, A.; Limbach, H. H. Isot.
Eff. Chem. Biol. 2006, 765–792. (d) Sohtome, Y.; Nagasawa, K. Synlett
2010, 1, 1–22.(e) Kuroki, S. In Modern Magnetic Resonance; Webb, G. A.,
Ed.; 2006; Vol. 1, pp 27À31. (f) Noujeim, N.; Leclercq, L.; Schmitzer,
A. R. Curr. Org. Chem. 2010, 14 (14), 1500–1516.
(6) For recent important reviews, see:(a) Dykstra, C. E. Theory Appl.
Comput. Chem.: First Forty Years 2005, 831–857. (b) Hobza, P.; Havlas,
Z. Chem. Rev. 2000, 100 (11), 4253–4264. (c) Scheiner, S. Adv. Mol.
Struct. Res. 2000, 6, 159–207. (d) Aakeroy, C. B.; Leinen, D. S. NATO
Sci. Ser., Ser. C: Math. Phys. Sci. 1999, 538, 89–106(Special Issue on:
Crystal Engineering: From Molecules and Crystals to Materials).
(e) Braga, D.; Grepioni, F.; Desiraju, G. R. Chem. Rev. 1998, 98, 1375.
(f) Lehn, J. M. Supramolecular Chemistry; VCH: Weinheim, 1995.
(7) For an important review:(a) Takahashi, O.; Kohno, Y.;Nishio, M.
Chem. Rev. 2010, 110 (10), 6049–6076. (b) Chan, M. C. W. Macromol.
Chem. Phys. 2007, 208 (17), 1845–1852. (c) Desiraju, G. R. Chem.
Commun. 2005, 24, 2995–3001. (d) Velcescu, A.; Blaise, P.; Henri-
Rousseau, O. Trends Chem. Phys. 2004, 11, 1–58. (e) Braga, D.; Grepioni,
F.; Desiraju, G. R. Chem. Rev. 1998, 98, 1375.(f) Lehn, J. M. Supramo-
lecular Chemistry; VCH: Weinheim, 1995. (g) Desiraju, G. R. Angew.
Chem., Int. Ed. Engl. 1995, 34, 2311.
(14) (a) Soloshonok, V. A.; Ueki, H.; Yasumoto, M.; Mekala, S.;
Hirschi, J. S.; Singleton, D. A. J. Am. Chem. Soc. 2007, 129, 12112–12113.
(b) Yasumoto, M.; Ueki, H.; Ono, T.; Katagiri, T.; Soloshonok, V. A.
J. Fluorine Chem. 2010, 131, 535. (c) Yasumoto, M.; Ueki, H.; Soloshonok,
V. A. J. Fluorine Chem. 2010, 131, 266. (d) Ueki, H.; Yasumoto, M.;
Soloshonok, V. A. Tetrahedron: Asymmetry 2010, 21, 1396. (e) Basiuk,
V. A.; Gromovoy, T. Y.; Chuiko, A. A.; Soloshonok, V. A.; Kukhar, V. P.
Synthesis 1992, 449–451.
(15) Shan, Z. X.; Xiong, Y.; Yi, J.; Hu, X. Y. J. Org. Chem. 2008, 73
(22), 9158. Hu, X. Y.; Shan, Z. X.; Li, W. J. Fluorine Chem. 2010, 131 (4),
505.
(16) Frankland, P. F.; Twiss, D. F. J. Chem. Soc., Perkin Trans. 1904,
85, 1666.
(17) Final atomic coordinates of the crystal for (4R,5R)-2, along
with lists of anisotropic thermal parameters, hydrogen coordinates, bond
lengths, and bond angles, have been deposited with the Cambridge
Crystallographic Data Centre as supplementary publication no. 759035.
Data can be obtained, on request, from the Director, Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ,
U.K. (fax: (+44) 1223-336-033; e-mail: deposit@ccdc.cam.cn; web:
http//www.ccdc.cam.ac.uk).
(18) The van der Waals radii for C, H, O, and Cl are 1.72, 1.10, 1.40,
and 1.80 Å (Pauling, L. The nature of the chemical bond), respectively. In
(4R,5R)-2, the distances between the Cl and the ortho-H's of the axial
ꢀ
ꢀ
and equatorial phenyl planes are 2.562 Å and 2.804 Å, respectively, being
shorter than the sum (2.90 Å) of the van der Waals radii for H and Cl. On
the other hand, the angles for Ca—H—Cl and Cq—H—Cl are 108.41°
and 96.53°, respectively. These data are true of the two basic crystal-
lographic characteristics of the C—H E weak H-bond presented by
3 3 3
Taylor and Kennard.9 Similar crystallographic characteristics of the
intramolecular C—Ho O (the 1,3,2-dioxathiolane ring) and inter-
3 3 3
molecular C—Hm O (the SdO) weak H bonds were also observed.
3 3 3
(19) Thallapally, P. K.; Nangia, A. CrystEngComm 2001, 27, 1–6.
(20) (a) Bellamy, L. J. Advances in Infrared Group Frequencies;
Methuen: 1968. (b) Cross, A. D.; Jones, R. A. An Introduction to Practical
Infrared Spectroscopy, 3rd ed.; Butterworths: 1960.
(8) Glasstone, S. Trans. Faraday Soc. 1937, 33, 200.
(9) Taylor, R.; Kennard, O. J. Am. Chem. Soc. 1982, 104, 5063–5070.
(10) For recent important works, see:(a) Hua, Y.; Ramabhadran,
R. O.; Uduehi, E. O.; Karty, J. A.; Raghavachari, K.; Flood, A. H. Chem.—
Eur. J. 2011, 17 (1), 312–321, S312/1ÀS312/24. (b) Xie, Y. P.; Yang, J.;
Ma, J. F.; Ma, J. C.; Zhang, L. P.; Jia, Z. F.; Su, Z. M. Cryst. Growth Des.
2009, 9 (9), 3881–3888. (c) Guo, F.; Zhang, S.; Guan, H.-Y.; Lu, N.;
Guo, W.-S. J. Coord. Chem. 2011, 64 (13), 2223–2233. (d) Puntus, L. N.
Helv. Chim. Acta 2009, 92 (11), 2552–2564. (e) Kefi, R.; Jeanneau, E.;
Lefebvre, F.; Ben Nasr, C. Acta Crystallogr., Sect. C: Cryst. Struct.
Commun. 2011, C67 (5), m126–m129. (f) Alcalde, E.; Mesquida, N.;
Vilaseca, M.; Alvarez-Rua, C.; Garcia-Granda, S. Supramol. Chem. 2007,
19 (7), 501–509. (g) Chandrasekhar, V.; Baskar, V.; Kingsley, S.;
Nagendran, S.; Butcher, R. J. Cryst. Eng. Comm. 2001, 17, 1–3.
(h) Banerjee, R.; Desiraju, G. R.; Mondal, R.; Howard, J. A. K.
Chem.—Eur. J. 2004, 10, 3373–3383.
(21) (a) Seebach, D.; Beck, A. K; Hayakawa, M.; Jaeschke, G.;
K€uhnle, F. N. M.; N€ageli, I.; Pinkerton, A. B.; Rheiner, P. B.; Duthaler,
R. O.; Rothe, P. M.; Weigand, W.; W€unsch, R.; Dick, S.; Nesper, R.;
W€orle, M.; Gramlich, V. Bull. Soc. Chim. Fr. 1997, 134, 315–331.
(b) Seebach, D.; Hayakawa, M.; Sakaki, J.; Schweizer, W. B. Tetrahedron
1993, 49, 1711–1724.
(11) For recent important works, see:(a) Fillion, E.; Wilsily, A.;
Fishlock, D. J. Org. Chem. 2009, 74 (3), 1259–1267. (b) Mallinson, P. R.;
Smith, G. T.; Wilson, C. C.; Grech, E.; Wozniak, K. J. Am. Chem. Soc.
2003, 125 (14), 4259–4270. (c) Kumar, V. S. S.; Pigge, F. C.; Rath, N. P.
Cryst. Eng. Comm. 2004, 6, 102–105. (d) Souza, M. V. N.; de; Pinheiro,
A. C.; Tiekink, E. R. T.; Wardell, S. M. S. V.; Wardell, J. L. Acta
Crystallogr., Sect. E: Struct. Rep. Online 2011, E67 (7), o1868–o1869.
(12) (a) Zhou, Y.; Shan, Z. X. J. Org. Chem. 2006, 71 (25), 9510.
(b) Zhou, Y.; Shan, Z. X.; Wang, B. S.; Xie, P. Organometallics 2006
36
dx.doi.org/10.1021/cg201219g |Cryst. Growth Des. 2012, 12, 33–36