Hypervalent iodine reagent mediated diamination of [60]fullerene with sulfamides or phosphoryl diamides

Article abstract of DOI:10.1021/ol5028305

A hypervalent iodine-promoted intermolecular diamination reactions of C₆₀ with sulfamides or phosphoryl diamides affords two classes of novel C₆₀-fused cyclic sulfamide or phosphoryl diamide derivatives. The reaction between C₆₀ and sulfamides can be effectively controlled to selectively synthesize diamination products or azafulleroids under PhIO/I₂ or PhI(OAc)₂/I₂ conditions, respectively. Moreover, phosphoryl diamides were first used as an amine source in the diamination of alkenes.

Full text of DOI:10.1021/ol5028305

Letter
pubs.acs.org/OrgLett
Hypervalent Iodine Reagent Mediated Diamination of [60]Fullerene
with Sulfamides or Phosphoryl Diamides
Hai-Tao Yang,* Xin-Wei Lu, Meng-Lei Xing, Xiao-Qiang Sun, and Chun-Bao Miao*
School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
S
* Supporting Information
ABSTRACT: A hypervalent iodine-promoted intermolecular
diamination reactions of C60 with sulfamides or phosphoryl
diamides affords two classes of novel C60-fused cyclic sulfamide
or phosphoryl diamide derivatives. The reaction between C60
and sulfamides can be effectively controlled to selectively
synthesize diamination products or azafulleroids under PhIO/I2
or PhI(OAc)2/I2 conditions, respectively. Moreover, phosphor-
yl diamides were first used as an amine source in the
diamination of alkenes.
hemical modification on the sphere of C60 allows the
Scheme 1
C
preparation of large quantities of fullerene derivatives with
different structures and properties for the investigation of their
application in biological and material science. Until now, a variety
of methods for chemical functionalization of fullerenes have been
explored involving various [2 + n] (n = 1−4) reactions, redox
reactions, cycloadditions, radical additions, nuclophilic additions,
and multiadditions.1 Free-radical reactions were one of the most
investigated reactions in fullerene chemistry and continue to be
an effective strategy for the functionalization of fullerenes. To
date, the addition of different kinds of radicals (e.g., C-, Si-, O-, S-,
and P-centered radicals) to fullerenes has been well docu-
mented.2 Multiaddition is liable to occur when free radicals react
with fullerenes and tend to give a reaction mixture containing
many and hardly separable products.3 Therefore, controlling the
single-addition of free-radicals to C60 is a challenge. Later, radical
reactions of fullerenes promoted by transition-metal salts such as
Mn(III),4 Cu(II),2d,5 Fe(III),6 and Pb(IV)7 to generate the
monoadduct were developed. The Orfanopoulos group explored
a photochemical addition of acyl and α-oxygen C-centered
radicals to fullerene catalyzed by TBADT [(n-Bu4N)4W10O32].8
Recently, cobalt-catalyzed radical hydroalkylation or cyclo-
addition of C60 with active alkyl bromides or dibromides was
demonstrated.2e,9 In contrast to the most investigated addition of
C-centered radicals to fullerenes, the addition of N-centered
radicals to fullerenes was rather rare. Only a few reactions of C60
with nitriles, amidines, amides, and carbamates based on N-
centered radicals were exploited.2c,10 Recently, we developed a
hypervalent iodine reagent/I2 system-mediated or CuI-catalyzed
N-centered radical reactions of C60 with amines/amides/
amidines.5c,11
this approach was limited to an intramolecular addition fashion,
and the use of phosphoryl diamides as amine source has never
been investigated. The new methods for the preparation of
fullerooxazoles and iminofullerenes explored by us and
Minakata’s group11,14 disclosed the nitrogen radicals were easy
to generate through N−I bond cleavage from the N,N-diiodo
intermediate and took place radical reaction with C60. Inspired by
these results, we could envision that treatment of sulfamides or
phosphoryl diamides with hypervalent iodine reagents/I2 would
generate the N,N′-diiodo intermediate, which might be captured
by C60 in a radical pathway to generate novel C60-fused cyclic
diamine derivatives (Scheme 1).
We began our investigation with the PhI(OAc)2/I2-mediated
reaction of C60 with N,N′-dibutylsulfamide 1a (Table 1). When a
mixture of C60 and 2 equiv of 1a was treated with 2 equiv of
PhI(OAc)2 and 2 equiv of I2 in chlorobenzene at room
temperature for 6 h, to our disappointment, one of the butyl
groups on the nitrogen atom was leaving, and azafulleroid 3a was
obtained as the main product along with trace of diamination
product 2a (Table 1, entry 5). We were fortunate to find that the
ratio of 2a to 3a could be inverted in favor of diamination when
Oxidative diamination of olefins with sulfamides has recently
emerged as a suitable approach to generate bicyclic sulfamides.
This strategy has been successfully employed by using [Ni], [Pd]
catalysts, or stoichiometric copper reagents (Scheme 1).12
Recently, the nonmetal-based methods received more attention
in alkene diamination with different amine sources.13 However,
Received: September 25, 2014
© XXXX American Chemical Society
A
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Letter
Table 1. Selective Reaction of C60 with N,N′-Dibutylsulfamide
Table 2. Reaction of C60 with Sulfamides under PhIO/I2
Conditions
Mediated by PhIO/I2 or PhI(OAc)2/I2
b
yield (%)
[C60/1a/hypervalent
time
(h)
entry conditions
iodine/I2]
2
3
1
2
3
4
5
6
7
8
A
A
A
A
B
B
B
B
1:2:2:2
1:2:2:0.2
1:2:3:1
1:2:4:1
1:2:2:2
1:2:2:0.2
1:2:3:1
1:2:4:1
6
24
12
6
28 (82)
10 (86)
22 (83)
30 (69)
trace
trace
trace
trace
trace
6
24 (79)
11 (89)
21 (75)
19 (63)
24
12
trace
trace
6
trace
a
b
C60 (36 mg), rt, 10 mL of chlorobenzene. Isolated yield; values in
parentheses are based on consumed C60.
PhI(OAc)2 was replaced by PhIO. Under PhIO/I2 conditions, 2a
was obtained in 28% yield accompanied by a trace of 3a (Table 1,
entry 1). Catalytic loading of I2 led to a dramatic decrease in the
yield (Table 1, entries 2 and 6). Increasing the amount of
hypervalent iodine to 3−4 equiv did not result in notable
improvement on the yield (Table 1, entries 3, 4, 7, and 8). It
should be pointed out that both hypervalent iodine and I2 were
essential to the reaction, and no reaction occurred in the absence
of either one.
a
Isolated yield; values in parentheses are based on consumed C60.
Irradiation with 125 W fluorescent high pressure mercury amp.
b
Table 3. Reaction of C60 with Sulfamides under PhI(OAc)2/I2
Conditions
It was intriguing that 2a and 3a could be selectively obtained
under PhIO/I2 and PhI(OAc)2/I2 systems, respectively. To
investigate the generality of the two kinds of selective
transformations, the optimized conditions (Table 1, entries 1
and 5) were applied for a number of different substituted
sulfamides 1a−i (Tables 2 and 3). Under PhIO/I2 conditions,
when R1 and R2 are both aliphatic groups, the reaction proceeded
well to give the diamination products 2 (Table 2, entries 1−6). If
one of the substituents on the nitrogen atom was ester group, the
yield decreased notably (Table 2, entry 7). The cyclic sulfamide
1h also afforded the desired product 2h in lower yield with the
assistance of photoirradiation (Table 2, entry 8). It was a pity that
an aromatic substituent on the nitrogen atom resulted in the
failure of the reaction (Table 2, entry 9).
As can be seen from the results mentioned in Table 1, one
substituent disappeared in the product. The symmetric
sulfamides gave the main product 3a and 3b as expected
(Table 3, entries 1 and 2). When the R1 and R2 were different
aliphatic groups, an interesting phenomenon was observed
(Table 3, entries 3−5). Only one main product was observed for
1c−e. The sequence of leaving ability of the group is Bn- > n-
butyl- > cyclohexyl-. For the substrate 1e, 5% of the diamination
product 2e was isolated accompanying with the main product 3d.
In terms of substrates 1f and 1g, only the diamination product 2f
a
entry
sulfamides
time (h)
product and yield
n
1
2
3
4
5
6
7
8
9
1a
1b
1c
1d
1e
1f
8
8
3a, 24% (82%) (R = C4H9 )
3b, 29% (87%) (R = Bn)
3a, 22% (79%)
8
8
3d, 27% (85%) (R = cyclohexyl)
3d, 23% (65%) and 2e, 5% (14%)
2f, 20% (71%)
8
6
1g
1h
1i
6
2g, 18% (67%)
8
NR
12
NR
a
Isolated yield; values in parentheses are based on cosumed C60.
and 2g was afforded under either PhI(OAc)2/I2 or PhIO/I2
conditions. For cyclic sulfamide 1g, no product was observed
under PhI(OAc)2/I2 conditions.
To gain insight into the selective transformation, several
control experiments were carried out (Scheme 2). Togo and co-
B
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Letter
Addition of 6 to C60 gave the fullerene radical 8. Subsequent N-
iodination, N−I bond cleavage, and intramolecular coupling
afforded the diamination product. Under PhI(OAc)2/I2
conditions, HOAc was generated in the first step of iodination,
which promoted the hydrolysis of 7 to 4 in the presence of a trace
of water in the air. N,N-Diodination of 4 provided 11, which
underwent a radical reaction with C60 to give azafullroid 3b.
Under PhIO/I2 conditions, the absence of acid inhibited the
decomposition of 7. Therefore, the formation of azafullroid 3b
was suppressed and diamination product 2b was predominant.
Encouraged by the good results, we next turned our attention
to phosphoryl diamides 12a and 12b, which have never been
used as the amine source in the diamination of olefins (Table 4).
Scheme 2. Controlled Experiments
Table 4. Reaction of C60 with Phosphoryl Diamides
workers have reported the oxidative dealkylation of N-
alkylsulfonamides to free sulfonamides and aldehydes under
PhI(OAc)2/I2 conditions.15 Treatment of C60 and N-benzylsul-
famide 4 with PhI(OAc)2/I2 indeed afforded the azafulleroid 3b.
This meant that 1b might be transformed to 4 promoted by
PhI(OAc)2/I2. Why was the diamination product was the main
product under PhIO/I2 conditions? We thought that the
essential factor was whether the imine intermediate 7, which
was generated from 5 via oxidative elimination of HI, could be
easily decomposed to 4 (Scheme 3). When the reaction of C60
a
yield (%)
time
entry substrate
conditions
PhIO/I2
(h)
13
14
1
2
3
4
12a
12a
12a
12a
6
6
0
0
29 (82)
26 (79)
25 (70)
trace
PhI(OAc)2/I2
PhI(OAc)2/I2, hν
6
trace
Scheme 3. Proposed Reaction Mechanism
PhI(OAc)2/I2, hν, N2, 4 Å
MS
12
16 (77)
5
6
7
12b
12b
12b
PhI(OAc)2/I2
6
6
0
24 (76)
25 (69)
trace
PhI(OAc)2/I2, hν
trace
14 (65)
PhI(OAc)2/I2, hν, N2, 4 Å
MS
12
a
Isolated yield; values in parentheses are based on consumed C60.
In contrast to sulfamides, PhIO and PhI(OAc)2 did not show
obvious distinction for phosphoryl diamides. Under either
PhIO/I2 or PhI(OAc)2/I2 conditions, the reaction of C60 with
12a did not furnish the anticipated diamination product 13a.
Instead, the aziridinofullerene 14 generated from the P−N bond
cleavage was produced as the main product (Table 4, entries 1
and 2). It should be noted that only trace of cis-1-
bisaziridinofullerene, which was inevitably generated in our
previously reported PhI(OAc)2/I2-mediated reaction of C60 with
alkyl amine,11b was observed in this reaction. Thus, this method
was a good choice for selectively preparing aziridinefullerene
(single-addition) bearing an alkyl group on the nitrogen atom. If
the reaction was performed under the irradiation of a 125 W
fluorescent high pressure Hg lamp, although the aziridinofuller-
ene 14 was still the main product, trace of diamination product
13a was observed on TLC (Table 4, entry 3). When the reaction
was carried out under N2 atmosphere with the addition of 4 Å
molecular sieve, to our delight, the formation of 14 was
suppressed notably and the diamination product 13a was isolated
as the main products. In case of phosphoryl diamide 12b, similar
result was obtained as that of 12a.
with 1a and PhIO/I2 was performed with 6 equiv of HOAc as the
additive, only a trace of 2a could be observed on TLC and 3a was
obtained in 22% yield. Moreover, if the reaction of C60 with 1a
and PhI(OAc)2/I2 was performed under N2 atmosphere with 4 Å
molecular sieves as the additive, diamination product 2a was
formed in 19% yield accompanying with trace of 3a. This could
be explained by the trace of water, and acidic conditions were
favorable to the hydrolysis of 7, which led to the formation of 3a.
On the basis of these results and our previous work on the
hypervalent iodine-mediated reaction of C60 with amines,11
a
Although the addition of diamines to C60 under photo-
irradiation or heating has been well investigated for the synthesis
of cyclic diamine-fused C60 derivatives,16 the substrates were
limited to N,N′-dialkyl-substituted ethylenediamine and piper-
azine compounds. Moreover, an electron-transfer process, which
radical reaction mechanism for the selective transformation is
proposed in Scheme 3. N-Iodo intermediate 5 was generated
under both reaction conditions. N−I bond cleavage and
elimination of HI would afford radical 6 and imine 7, respectively.
C
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2014, 16, 1020. (e) Lu, S.; Si, W.; Bao, M.; Yamamoto, Y.; Jin, T. Org.
Lett. 2013, 15, 4030.
was quite different with the present method, was involved in the
reaction. The recently emerged intramolecular diamination of
alkenes under metal-free conditions mostly underwent an ionic
pathway.13
The structures of new diamination products 2 and 13 and
azafulleroids 3 were fully assigned on the basis of their MALDI-
TOFMS, 1H NMR, 13C NMR, and UV−vis spectra. Taking 2a as
an example, the TOFMS spectrum of 3a showed the [M + Na]+
peak at m/z 949.0981. The 1H NMR spectrum of 3a displayed
four signals for the butyl group. The 13C NMR spectrum of 3a
exhibited 16 signals (3 × 2C, and 13 × 4C) for the sp2-C of the
C60 skeleton in the range of 137.74−148.31 ppm and one peak at
79.32 ppm for the sp3-C of the C60 cage, agreeing well with the
C2v symmetry of its molecular structure.
In summary, we have developed a hypervalent iodine-
mediated intermolecular diamination of C60 with sulfamides or
phosphoryl diamides for the synthesis of novel C60-fused cyclic
sulfamide or C60-fused cyclic phosphoryl diamide derivatives,
which constitute two new classes of the fullerene family.
Compared with previously reported methods for the diamination
of olefins with sulfamides, this novel protocol is distinguished by
(1) an intermolecular addition fashion; (2) metal-free
conditions; (3) radical pathway; (4) first use of phosphoryl
diamides as amine source; and (5) mild conditions.
(3) (a) Krusic, P. J.; Wasserman, E.; Parkinson, B. A.; Malone, B.;
Holler, E. R.; Keizer, P. N.; Morton, J. R.; Preston, K. F. J. Am. Chem. Soc.
1991, 113, 6274. (b) Krusic, P. J.; Wasserman, E.; Keizer, P. N.; Preston,
K. F. Science 1991, 254, 1183. (c) Troyanov, S. I.; Dimitrov, A.; Kemnitz,
E. Angew. Chem., Int. Ed. 2006, 45, 1971. (d) Omelyanyuk, N. A.;
Goryunkov, A. A.; Tamm, N. B.; Avdoshenko, S. M.; Ioffe, I. N.; Sidorov,
L. N.; Kemnitz, E.; Troyanov, S. I. Chem. Commun. 2007, 4794.
(4) For reviews, see: (a) Wang, G.-W.; Li, F.-B. J. Nanosci. Nanotechnol.
2007, 7, 1162. (b) Wang, G.-W.; Li, F.-B. Curr. Org. Chem. 2012, 16,
1109.
(5) (a) Wang, G.-W.; Li, F.-B. Org. Biomol. Chem. 2005, 3, 794. (b) Lu,
S.; Jin, T.; Kwon, E.; Bao, M.; Yamamoto, Y. Angew. Chem., Int. Ed. 2012,
51, 802. (c) Yang, H.-T.; Liang, X.-C.; Wang, Y.-H.; Yang, Y.; Sun, X.-Q.;
Miao, C.-B. Org. Lett. 2013, 15, 4650. (d) Yang, H.-T.; Liang, X.-C.;
Wang, Y.-H.; Yang, Y.; Sun, X.-Q.; Miao, C.-B. J. Org. Chem. 2013, 78,
11992.
(6) For a review, see: Li, F.-B.; Wang, G.-W. Sci. China Chem. 2012, 55,
2009.
(7) (a) Li, F.-B.; Liu, T.-X.; Huang, Y.-S.; Wang, G.-W. J. Org. Chem.
2009, 74, 7743. (b) Chuang, S.-C.; Clemente, F. R.; Khan, S. I.; Houk, K.
N.; Rubin, Y. Org. Lett. 2006, 8, 4525.
(8) (a) Tzirakis, M. D.; Orfanopoulos, M. Org. Lett. 2008, 10, 873.
(b) Tzirakis, M. D.; Orfanopoulos, M. J. Am. Chem. Soc. 2009, 131, 4063.
(c) Tzirakis, M. D.; Orfanopoulos, M. Angew. Chem., Int. Ed. 2010, 49,
5891. (d) Tzirakis, M. D.; Alberti, M. N.; Orfanopoulos, M. Chem.
Commun. 2010, 8228.
(9) Lu, S.; Jin, T.; Bao, M.; Yamamoto, Y. J. Am. Chem. Soc. 2011, 133,
12842.
(10) (a) Li, F.-B.; Liu, T.-X.; Wang, G.-W. J. Org. Chem. 2008, 73, 6417.
(b) He, C.-L.; Liu, R.; Li, D.-D.; Zhu, S.-E.; Wang, G.-W. Org. Lett. 2013,
15, 1532. (c) Takeda, Y.; Enokijima, S.; Nagamachi, T.; Nakayama, K.;
Minakata, S. Asian J. Org. Chem. 2013, 2, 91.
ASSOCIATED CONTENT
* Supporting Information
■
S
Experimental details and NMR spectra of the products. This
material is available free of charge via the Internet at http://pubs.
acs.org.
(11) (a) Yang, H.-T.; Ren, W.-L.; Dong, C.-P.; Yang, Y.; Sun, X.-Q.;
Miao, C.-B. Tetrahedron Lett. 2013, 54, 6799. (b) Miao, C.-B.; Lu, X.-W.;
Wu, P.; Li, J.-X.; Ren, W.-L.; Xing, M.-L.; Sun, X.-Q.; Yang, H.-T. J. Org.
Chem. 2013, 78, 12257.
AUTHOR INFORMATION
Corresponding Authors
■
*E-mail: yht898@yahoo.com.
*E-mail: estally@yahoo.com.
Notes
(12) For a review, see: (a) Muniz, K.; Martínez, C. J. Org. Chem. 2013,
̃
78, 2168 and references cited therein.
(13) (a) Ortiz, G. X., Jr.; Kang, B.; Wang, Q. J. Org. Chem. 2014, 79,
571. (b) Hong, K. B.; Johnston, J. N. Org. Lett. 2014, 16, 3804 and
The authors declare no competing financial interest.
references cited therein. (c) Souto, J. A.; Gonzal
́
ez, Y.; Iglesias, A.; Zian,
D.; Lishchynskyi, A.; Muniz, K. Chem.Asian J. 2012, 7, 1103.
̃
ACKNOWLEDGMENTS
■
(d) Chav
Belmonte, M.; Escudero-Adan
2012, 3, 2375.
́
ez, P.; Kirsch, J.; Hovelmann, C. H.; Streuff, J.; Martínez-
̈
We are grateful for financial support from the National Natural
Science Foundation of China (Nos. 20902039 and 21202011),
Natural Science Foundation of Jiangsu Province (BK20141171),
the Priority Academic Program Development of Jiangsu Higher
Education Institutions (PAPD), and the Jiangsu Key Laboratory
of Advanced Catalytic Materials and Technology (BM2012110).
́
, E. C.; Martin, E.; Muniz, K. Chem. Sci.
̃
(14) (a) Nagamachi, T.; Takeda, Y.; Nakayama, K.; Minakata, S.
Chem.Eur. J. 2012, 18, 12035. (b) Takeda, Y.; Enokijima, S.;
Nagamachi, T.; Nakayama, K.; Minakata, S. Asian J. Org. Chem. 2013, 2,
91.
(15) Katohgi, M.; Togo, H. Tetrahedron 2001, 57, 7481.
(16) (a) Kampe, K. D.; Egger, N.; Vogel, M. Angew. Chem., Int. Ed. Engl.
1993, 32, 1174. (b) Kampe, K. D.; Egger, N. Liebigs Ann. 1995, 115.
(c) Butts, C. P.; Jazdzyk, M. Chem. Commun. 2003, 1530−1531.
(d) Wang, N.-X. Tetrahedron 2002, 58, 2377.
REFERENCES
■
(1) For books, see: (a) Hirsch, A.; Brettreich, M. Fullerenes: Chemistry
and Reactions; Wiley−VCH: Weinheim, 2005. (b) Langa, F.;
Nierengarten, J.-F. Fullerenes: Principles and Applications; RSC Publish-
ing: Cambridge, 2007. For recent representative works, see:. (c) Xiao,
Y.; Zhu, S.-E.; Liu, D.-J.; Suzuki, M.; Lu, X.; Wang, G.-W. Angew. Chem.,
Int. Ed. 2014, 53, 3006. (d) Si, W.; Lu, S.; Bao, M.; Asao, N.; Yamamoto,
Y.; Jin, T. Org. Lett. 2014, 16, 620. (e) Zhai, W.-Q.; Peng, R.-F.; Jin, B.;
Wang, G.-W. Org. Lett. 2014, 16, 1638. (f) Chang, W.-W.; Li, Z.-J.; Gao,
X. Org. Lett. 2013, 15, 1642. (g) Takeda, Y.; Kawai, H.; Minakata, S.
Chem.−Eur. J. 2013, 19, 13479. (h) Liang, S.; Xu, L.; Jia, Z.; Gan, L. J.
Org. Chem. 2014, 79, 5794.
(2) For a review, see: (a) Tzirakis, M. D.; Orfanopoulos, M. Chem. Rev.
2013, 113, 5262. For recent selected works, see: (b) Miyaka, Y.; Ashida,
Y.; Nakajima, K.; Nishibayashi, Y. Chem.Eur. J. 2014, 20, 6120.
(c) You, X.; Wang, G.-W. J. Org. Chem. 2014, 79, 117. (d) Liu, T.-X.;
Zhang, Z.; Liu, Q.; Zhang, P.; Jia, P.; Zhang, Z.; Zhang, G. Org. Lett.
D
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