Intramolecular C-N bond formation reactions catalyzed by ruthenium porphyrins: Amidation of sulfamate esters and aziridination of unsaturated sulfonamides

Article abstract of DOI:10.1021/jo0358877

Ruthenium porphyrins [Ru(F₂₀-TPP)(CO)] (F₂₀-TPP = 5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato dianion) and [Ru(Por*)(CO)] (Por* = 5,10,15,20-tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-octahydro-1,4:5, 8-dimethanoanthracen-9-yl]porphyrinato dianion) catalyzed intramolecular amidation of sulfamate esters p-X-C₆H₄(CH ₂)₂OSO₂NH₂ (X = Cl, Me, MeO), XC₆H₄(CH₂)₃OSO₂NH ₂ (X = p-F, p-MeO, m-MeO), and Ar(CH₂)₂OSO ₂NH₂ (Ar = naphthalen-1-yl, naphthalen-2-yl) with PhI(OAc)₂ to afford the corresponding cyclic sulfamidates in up to 89% yield with up to 100% substrate conversion; up to 88% ee was attained in the asymmetric intramolecular amidation catalyzed by [Ru(Por*)(CO)]. Reaction of [Ru(F₂₀-TPP)(CO)] with PhI=NSO₂OCH ₂CCl₃ (prepared by treating the sulfamate ester Cl ₃CCH₂OSO₂NH₂ with PhI(OAc) ₂) afforded a bis(imido)ruthenium(VI) porphyrin, [Ru ^VI(F₂₀-TPP)(NSO₂OCH₂CCl ₃)₂], in 60% yield. A mechanism involving reactive imido ruthenium porphyrin intermediate was proposed for the ruthenium porphyrin-catalyzed intramolecular amidation of sulfamate esters. Complex [Ru(F₂₀-TPP)(CO)] is an active catalyst for intramolecular aziridination of unsaturated sulfonamides with PhI(OAc)₂, producing corresponding bicyclic aziridines in up to 87% yield with up to 100% substrate conversion and high turnover (up to 2014).

Full text of DOI:10.1021/jo0358877

In tr a m olecu la r C-N Bon d F or m a tion Rea ction s Ca ta lyzed by
Ru th en iu m P or p h yr in s: Am id a tion of Su lfa m a te Ester s a n d
Azir id in a tion of Un sa tu r a ted Su lfon a m id es
J iang-Lin Liang, Shi-Xue Yuan, J ie-Sheng Huang, and Chi-Ming Che*
Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular
Technology for Drug Discovery and Synthesis, The University of Hong Kong, Pokfulam Road, Hong Kong
cmche@hku.hk
Received December 30, 2003
Ruthenium porphyrins [Ru(F20-TPP)(CO)] (F20-TPP ) 5,10,15,20-tetrakis(pentafluorophenyl)-
porphyrinato dianion) and [Ru(Por*)(CO)] (Por* ) 5,10,15,20-tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-
octahydro-1,4:5,8-dimethanoanthracen-9-yl]porphyrinato dianion) catalyzed intramolecular ami-
dation of sulfamate esters p-X-C6H4(CH2)2OSO2NH2 (X ) Cl, Me, MeO), XC6H4(CH2)3OSO2NH2 (X
) p-F, p-MeO, m-MeO), and Ar(CH2)2OSO2NH2 (Ar ) naphthalen-1-yl, naphthalen-2-yl) with PhI-
(OAc)2 to afford the corresponding cyclic sulfamidates in up to 89% yield with up to 100% substrate
conversion; up to 88% ee was attained in the asymmetric intramolecular amidation catalyzed by
[Ru(Por*)(CO)]. Reaction of [Ru(F20-TPP)(CO)] with PhIdNSO2OCH2CCl3 (prepared by treating
the sulfamate ester Cl3CCH2OSO2NH2 with PhI(OAc)2) afforded a bis(imido)ruthenium(VI) por-
phyrin, [RuVI(F20-TPP)(NSO2OCH2CCl3)2], in 60% yield. A mechanism involving reactive imido
ruthenium porphyrin intermediate was proposed for the ruthenium porphyrin-catalyzed intramo-
lecular amidation of sulfamate esters. Complex [Ru(F20-TPP)(CO)] is an active catalyst for
intramolecular aziridination of unsaturated sulfonamides with PhI(OAc)2, producing corresponding
bicyclic aziridines in up to 87% yield with up to 100% substrate conversion and high turnover (up
to 2014).
In tr od u ction
esters4b,5a and intramolecular aziridination of unsatur-
ated sulfonamides2b,3a-c,5b,c and sulfamate esters3d,4c in the
presence of manganese,1 iron,1 copper,3 ruthenium,5a and
dirhodium2,4,5b,c catalysts (routes I-VI in Scheme 1). The
intramolecular amidation and aziridination reactions of
sulfonamides were first studied by Breslow,1 Mu¨ller,2b
and co-workers, respectively, by preconversion of sul-
fonamide substrates into respective PhIdNSO2R com-
pounds through reaction with PhI(OAc)2 (routes I and
IV). Du Bois and co-workers4a,b realized direct intra-
molecular amidation with PhI(OAc)2 by employing car-
bamate and sulfamate ester substrates and dirhodium
catalysts (route II), like our earlier intermolecular PhI-
(OAc)2-amidation of sulfonamides catalyzed by ruthe-
nium and manganese complexes.6 Dodd and co-workers
reported the intramolecular aziridination or amidation
of unsaturated sulfonamides/sulfamate esters with
Intramolecular C-N bond formation reactions medi-
ated by transition-metal complexes provide a convenient
access to cyclic amines/amides or bicyclic aziridines. An
important type of such reactions involves iodine(III)
compounds PhIdNSO2R, PhIdO, or commercially avail-
able PhI(OAc)2 and possibly occurs via intramolecular
nitrogen atom transfer from putative metal imido (or
nitrene) species to saturated C-H bonds or alkene double
bonds.1-5 This hitherto includes the intramolecular ami-
dation of sulfonamides,1,2a carbamates,4a and sulfamate
(1) Breslow, R.; Gellman, S. H. J . Am. Chem. Soc. 1983, 105, 6728.
(2) (a) Mu¨ller, P. In Advances in Catalytic Processes, Vol. 2,
Asymmetric Catalysis; Doyle, M. P., Ed.; J AI Press: Greenwich, 1997;
p 113. (b) Mu¨ller, P.; Baud, C.; J acquier, Y. Can. J . Chem. 1998, 76,
738. (c) Mu¨ller, P.; Fruit, C. Chem. Rev. 2003, 103, 2905.
(3) (a) Dauban, P.; Dodd, R. H. Org. Lett. 2000, 2, 2327. (b) Dauban,
P.; Dodd, R. H. Tetrahedron Lett. 2001, 42, 1037. (c) Dauban, P.;
Sanie`re, L.; Tarrade, A.; Dodd, R. H. J . Am. Chem. Soc. 2001, 123,
7707. (d) Duran, F.; Leman, L.; Ghini, A.; Burton, G.; Dauban, P.; Dodd,
R. H. Org. Lett. 2002, 4, 2481. (e) Dauban, P.; Dodd, R. H. Synlett 2003,
1571.
(5) (a) Liang, J .-L.; Yuan, S.-X.; Huang, J .-S.; Yu, W.-Y.; Che, C.-M.
Angew. Chem., Int. Ed. 2002, 41, 3465. (b) Liang, J .-L.; Yuan, S.-X.;
Chan, P. W. H.; Che, C.-M. Org. Lett. 2002, 4, 4507. (c) Liang, J .-L.;
Yuan, S.-X.; Chan, P. W. H.; Che, C.-M. Tetrahedron Lett. 2003, 44,
5917.
(6) (a) Yu, X.-Q.; Huang, J .-S.; Zhou, X.-G.; Che, C.-M. Org. Lett.
2000, 2, 2233. (b) Au, S.-M.; Huang, J .-S.; Che, C.-M.; Yu, W.-Y. J .
Org. Chem. 2000, 65, 7858.
(4) (a) Espino, C. G.; Du Bois, J . Angew. Chem., Int. Ed. 2001, 40,
598. (b) Espino, C. G.; Wehn, P. M.; Chow, J .; Du Bois, J . J . Am. Chem.
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Soc. 2002, 124, 13672.
10.1021/jo0358877 CCC: $27.50 © 2004 American Chemical Society
Published on Web 05/05/2004
3610
J . Org. Chem. 2004, 69, 3610-3619

Intramolecular C-N Bond Formation Reactions
SCHEME 1. Sch em a tic Dia gr a m Dep ictin g th e
Meta l-Ca ta lyzed In tr a m olecu la r Am id a tion a n d
Azir id in a tion w ith Iod in e(III) Com p ou n d s (On ly
th e Key Moiety of th e Su bstr a te Is Sh ow n )
lecular amidation of sulfamate esters was initially con-
ducted for the reaction of sulfamate indan-2-yl ester (1a )
with PhI(OAc)2 in dichloromethane containing 1.5 mol
% of [Ru(F20-TPP)(CO)]. This reaction gave the corre-
sponding cyclic sulfamidate (2a ) in 52% yield (entry 1 in
Table 1) with virtually complete cis-selectivity. Subse-
quent examination of the reactions between 1a and PhI-
(OAc)2 in the presence of [Ru(F20-TPP)(CO)] under vari-
ous conditions (see entries 1-12 in Table 1) revealed that
the [Ru(F20-TPP)(CO)]-catalyzed amidation of 1a would
best be performed in dichloromethane at 40 °C in the
presence of additive Al2O3. Under these conditions, other
ruthenium porphyrins, [Ru(TPP)(CO)], [Ru(TMP)(CO)],
and [Ru(OEP)(CO)], could also catalyze the intramolecu-
lar amidation of 1a but gave 2a in substantially lower
yields (cf. entries 10, 13-15 in Table 1). Non-porphyrin
ruthenium complexes (1R,2R)-[Ru(Br4salen)(PPh3)2] and
[Ru(pybox-ip)Cl2(CH2dCH2)] and the iron and manga-
nese porphyrins [Fe(F20-TPP)Cl] and [Mn(F20-TPP)Cl]
were also examined and found to be inferior to [Ru(F20
-
TPP)(CO)] as a catalyst for this intramolecular amidation
process (cf. entries 10, 16-19 in Table 1). The intramo-
lecular PhI(OAc)2-amidation of a sulfamate ester cata-
lyzed by [Ru(F20-TPP)(CO)] has been extended to sub-
strates 1b-f (Chart 1) at a catalyst/substrate/PhI(OAc)2/
Al2O3 molar ratio of 0.015:1:2:2.5, affording cyclic
sulfamidates 2b-f in 56-88% yields with virtually
complete cis-selectivity for 2e,f.5a
To further expand the scope of the [Ru(F20-TPP)(CO)]-
catalyzed intramolecular amidation and inspect the effect
of substituents, we prepared a series of new sulfamate
esters 1g-o and examined their reactions with PhI(OAc)2
in the presence of [Ru(F20-TPP)(CO)] under the same
conditions as for 1b-f. The results are summarized in
Table 2.
PhIdO in the presence of copper catalysts (routes III and
VI).3b-d Recently, we communicated highly diastereo- and
enantioselective intramolecular PhI(OAc)2-amidation of
sulfamate esters catalyzed by ruthenium porphyrins5a
(route II) and intramolecular PhI(OAc)2-aziridination of
unsaturated sulfonamides catalyzed by dirhodium com-
plexes5b,c (route V). We now report here extensive inves-
tigations on the ruthenium porphyrin-catalyzed intra-
molecular PhI(OAc)2-amidation of sulfamate esters and
the first intramolecular PhI(OAc)2-aziridination of un-
saturated sulfonamides catalyzed by a ruthenium por-
phyrin (route V); the latter is so far the only example of
metalloporphyrin-catalyzed intramolecular aziridination
reactions.
It is evident that sulfamate esters 1g-n are good
substrates for the [Ru(F20-TPP)(CO)]-catalyzed intra-
molecular amidation. These catalytic intramolecular
C-N bond formation reactions produced cyclic sulfami-
Resu lts a n d Discu ssion
(7) (a) Baldwin, J . E.; Spivey, A. C.; Schofield, C. J . Tetrahedron:
Asymmetry 1990, 1, 881. (b) Aguilera, B.; Ferna´ndez-Mayotalas, A.
Chem. Commun. 1996, 127. (c) Corral, C.; Lissavetzky, J .; Manzanares,
I.; Darias, V.; Expo´sito-Orta, M. A.; Conde, J . A. M.; Sa´nchez-Mateo,
C. C. Bioorg. Med. Chem. 1999, 7, 1349. (d) Wei, L.; Lubell, W. D. Can.
J . Chem. 2001, 79, 94. (e) Nicolaou, K. C.; Huang, X.; Snyder, S. A.;
Rao, P. B.; Bella, M.; Reddy, M. V. Angew. Chem., Int. Ed. 2002, 41,
834. (f) Cohen, S. B.; Halcomb, R. L. J . Am. Chem. Soc. 2002, 124,
2534. (g) Posakony, J . J .; Grierson, J . R.; Tewson, T. J . J . Org. Chem.
2002, 67, 5164. (h) Williams, A. J .; Chakthong, S.; Gray, D.; Lawrence,
R. M.; Gallagher, T. Org. Lett. 2003, 5, 811. (i) Mele´ndez, R. E.; Lubell,
W. D. Tetrahedron 2003, 59, 2581.
In tr a m olecu la r Am id a tion of Su lfa m a te Ester s
Ca ta lyzed by Ach ir a l Ru th en iu m P or p h yr in s. As
shown in Scheme 1, intramolecular amidation of sulfa-
mate esters (X/Y/m ) O/S/2 in Scheme 1a) with PhI(OAc)2
in the presence of metal catalysts affords cyclic sulfami-
dates, which are versatile reagents in organic synthesis4b,7
(for example, as useful precursors for preparing amino
acids,7a,d,e carbohydrates,7b and glycopeptides7f). Our pre-
vious work5a on ruthenium porphyrin-catalyzed intramo-
J . Org. Chem, Vol. 69, No. 11, 2004 3611

Liang et al.
TABLE 1. In tr a m olecu la r Am id a tion of Su lfa m a te In d a n -2-yl Ester (1a ) w ith P h I(OAc)2 Ca ta lyzed by Ru th en iu m
P or p h yr in s a n d Rela ted Meta l Com p lexesa
entry
catalyst
additive
solvent
CH2Cl2
CH2Cl2
CH3CN
C6H6
yieldb (%)
1
2
3
4
5
6
7
8
9
10
11c
12d
13
14
15
16
17
18h
19j
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(F20-TPP)(CO)]
[Ru(TPP)(CO)]e
[Ru(TMP)(CO)]f
[Ru(OEP)(CO)]g
[Mn(F20-TPP)Cl]
[Fe(F20-TPP)Cl]
(1R,2R)-[Ru(Br4salen)(PPh3)2]i
[Ru(pybox-ip)Cl2(CH2dCH2)]k
52
58
11
58
37
58
30
10
30
61
66
34
30
42
12
40
34
10
33
MgO
MgO
MgO
MgO
ClCH2CH2Cl
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
ZnO
K2CO3
NaOH
2,6-Cl2py
Al2O3
Al2O3
Al2O3
Al2O3
Al2O3
Al2O3
Al2O3
Al2O3
Al2O3
Al2O3
a
All reactions were performed at 40 °C for 2 h with a catalyst/1a /PhI(OAc)2/additive molar ratio of 0.015:1:2:2.5 (unless otherwise
denoted). Isolated yield based on the amount of starting 1a . c 5 mol % of 1 was added. At room temperature. e TPP ) 5,10,15,20-
b
d
tetraphenylporphyrinato dianion. f TMP ) 5,10,15,20-tetramesitylporphyrinato dianion. g OEP ) 2,3,7,8,12,13,17,18-octaethylporphyrinato
h
i
dianion. 12.5 mol % of catalyst was used, with 2a obtained in 8% ee. Br4salen ) 1,2-bis(3,5-dibromo-2-hydroxybenzylideneamino)-
j
k
cyclohexane dianion. 12.5 mol % of catalyst was used, with 2a obtained in 9% ee. pybox-ip ) bis(2-oxazolin-2-yl)pyridine.
CHART 1
dates 2g-n in 63-87% yields, with a regioselectiv-
ity similar to that observed for previously reported
analogues.4b,5a The intramolecular amidation of 1h ,i,l-n
proceeded with excellent substrate conversions of 92-
100%.
Competitive intramolecular amidation of p-X-C6H4-
(CH2)2OSO2NH2 (X ) Br, Cl (1g), H (1b), Me (1h ), and
OMe (1i)) catalyzed by [Ru(F20-TPP)(CO)] (see the Ex-
perimental Section) gave log(kX/kH) values of 0.137 (X )
MeO), 0.036 (X ) Me), -0.040 (X ) Br), and -0.041
(X ) Cl), indicating that electron-donating substituents
accelerate, whereas electron-withdrawing substituents
slow, the intramolecular amidation reactions. Fitting the
Inspection of entries 7-9 in Table 2 reveals that the
position of the substituent on sulfamate ester substrate
can affect the efficiency of the intramolecular amidation
process. On going from p-MeO-C6H4(CH2)3OSO2NH2 (1m )
to m-MeO-C6H4(CH2)3OSO2NH2 (1n ), the yield of the
resulting cyclic sulfamidate drops from 85% to 63%
(entries 7 and 8). Strikingly, for o-MeO-C6H4(CH2)3OSO2-
NH2 (1o), no cyclic sulfamidate 2o was detected in the
reaction mixture (the substrate largely remained un-
reacted). We attribute such a decrease in intramolecular
amidation efficiency along 1m f 1n f 1o to the increase
in steric interaction in the active amidation species (see
below).
+
log(kX/kH) values with Hammett constants σp resulted
in a linearity with R ) 0.99 and F ) -0.19 ( 0.01. The
+
log(kX/kH) vs σp plot is shown in Figure 1.
Asym m etr ic In tr a m olecu la r Am id a tion of Su lfa -
m a te Ester s Ca ta lyzed by Ch ir a l Ru th en iu m P or -
p h yr in . Metal-catalyzed enantioselective intramolecular
amidation of sulfamate esters is an attractive method for
the synthesis of optically active cyclic sulfamidates. Du
Bois and co-workers reported the synthesis of optically
pure cyclic sulfamidates from optically pure sulfamate
3612 J . Org. Chem., Vol. 69, No. 11, 2004

Intramolecular C-N Bond Formation Reactions
TABLE 2. In tr a m olecu la r Am id a tion of Su lfa m a te
Ester s 1g-o w ith P h I(OAc)2 in th e P r esen ce of Al2O3
Ca ta lyzed by [Ru (F 20-TP P )(CO)]a
TABLE 3. Asym m etr ic In tr a m olecu la r Am id a tion of
Su lfa m a te Ester s w ith P h I(OAc)2 in th e P r esen ce of
Al2O3 Ca ta lyzed by [Ru (P or *)(CO)]a
entry substrate product conversion (%) yieldb (%) eec (%)
1
2
3
4
5
6
7
8
9
1f
2f
79
60
68
91
60
58
58
65
59
<5
82
72
89
75
73
74
78
82
70
87
77
83
88d
86
83d
86
85
84
1g
1h
1i
1j
1k
1l
1m
1n
1o
2g
2h
2i
2j
2k
2l
2m
2n
2o
10
not detectable
a
Reaction conditions: benzene, 5 °C, 8 h, catalyst/substrate/
b
PhI(OAc)2/Al2O3 molar ratio ) 0.1:1:1.4:2.5. Isolated yield based
entry substrate product
conversion (%)
yieldb (%)
on the amount of consumed substrate. c Determined by HPLC
d
1
2
3
4
5
6
7
8
9
1g
1h
1i
1j
1k
1l
1m
1n
1o
2g
2h
2i
2j
2k
2l
2m
2n
2o
88
99
100
70
69
68
76
87
68
81
85
63
using chiral OD column. Determined by HPLC using chiral OJ
column.
81
values are much higher than that observed for the chiral
non-porphyrin ruthenium catalyst (1R,2R)-[Ru(Br4salen)-
(PPh3)2] (<10%, see entry 18 in Table 1).
100
100
92
10
not detectable
a
Reaction conditions: CH2Cl2, 40 °C, 2 h, catalyst/substrate/
b
PhI(OAc)2/Al2O3 molar ratio ) 0.015:1:2:2.5. Isolated yield based
on the amount of consumed substrate.
We have now extended the [Ru(Por*)(CO)]-catalyzed
asymmetric intramolecular PhI(OAc)2-amidation of sulfa-
mate ester to substrates 1f-o. Again, 1o is an unreactive
substrate, as in the intramolecular amidation catalyzed
by [Ru(F20-TPP)(CO)] described above. The reactions of
1f-n with PhI(OAc)2 in the presence of [Ru(Por*)(CO)],
under the same conditions as for substrates 1a -c, gave
respective optically active cyclic sulfamidates 2f-n in
70-89% yields and 77-88% ee, with virtually complete
cis-selectivity for 1f (see Table 3).
+
Note that [Ru(Por*)(CO)] is a less active catalyst than
[Ru(F20-TPP)(CO)] for the intramolecular amidation of
sulfamate esters.5a Considerably higher catalyst loading
(10 vs 1.5 mol %) was required to obtain the cyclic
sulfamidates in significant yields.
F IGURE 1. log(kX/kH) vs σp plot for the [Ru(F20-TPP)(CO)]-
catalyzed intramolecular amidation of para-substituted sulfa-
mate esters p-X-C6H4(CH2)2OSO2NH2 with PhI(OAc)2.
esters through dirhodium-catalyzed intramolecular ami-
dation with PhI(OAc)2,4b which has found great utility
in the synthesis of natural products manzacidins A and
C.8 Our previous work5a realized the first metal-catalyzed
enantioselective intramolecular amidation of prochiral
sulfamate esters by employing chiral ruthenium porphy-
rin [Ru(Por*)(CO)] as a catalyst. The [Ru(Por*)(CO)]-
catalyzed PhI(OAc)2-intramolecular amidation of 1a -c
and p-X-C6H4(CH2)2OSO2NH2 (X ) F, Br) resulted in
highest enantiocontrol in benzene at 5 °C with a catalyst/
substrate/PhI(OAc)2/Al2O3 molar ratio of 0.1:1:1.4:2.5,
affording, within 8 h, the corresponding optically active
cyclic sulfamidates in 20-48% yields and 82-87% ee,
with virtually complete cis-selectivity for 1a .5a These ee
The ee values observed for substrate series p-X-
C6H4(CH2)2OSO2NH2 (X ) Br,5a H: 1b,5a F,5a Me: 1h ,
OMe: 1i; ee ) 83-88%) or p-X-C6H4(CH2)3OSO2NH2
(X ) H: 1c,5a F: 1l, OMe: 1m ; ee ) 84-86%) are similar,
indicating that these para-substituents have insignificant
or little effect on the enantioselectivity of the intra-
molecular amidation reactions. As a matter of fact, all
the optically active cyclic sulfamidates 2f-n in Table 3
except 2g were obtained with similar ee values (83-88%).
The highest enantioselectivity (88% ee) attained in this
work is for the intramolecular amidation of 1i (entry 4
in Table 3), which, to our knowledge, is also the highest
enantiocontrol so far achieved for metal-catalyzed asym-
metric intramolecular amidation of saturated C-H bonds
utilizing iodine(III) compounds.
(8) Wehn, P. M.; Du Bois, J . J . Am. Chem. Soc. 2002, 124, 12950.
J . Org. Chem, Vol. 69, No. 11, 2004 3613

Liang et al.
SCHEME 2. Syn th esis of Bis(im id o)r u th en iu m (VI)
P or p h yr in [Ru VI(F 20-TP P )(NSO2OCH2CCl3)2]
On th e Mech a n ism of In tr a m olecu la r Am id a tion
of Su lfa m a te Ester s Ca ta lyzed by Ru th en iu m P or -
p h yr in s. Although metal-catalyzed intramolecular C-N
bond formation reactions depicted in Scheme 1 are
usually proposed to involve metal imido (or nitrene)
intermediates (like their intermolecular analogues9),
there has been no report in which a reactive metal imido
(or nitrene) species is isolated or directly observed for
such catalytic intramolecular reactions.
The intramolecular PhI(OAc)2-amidation of sulfamate
esters ROSO2NH2 catalyzed by metal complexes might
involve in situ generation of PhIdNSO2OR, since the
reactions between PhI(OAc)2 and RSO2NH2 are well
documented as a general method for preparation of stable
PhIdNSO2R compounds.10 Previously, we isolated PhId
NSO2O-indan-2-yl by treating PhI(OAc)2 with sulfamate
ester 1a .5a We also examined the intramolecular amida-
tion of PhIdNSO2O-indan-2-yl in the presence of catalyst
[Ru(Por*)(CO)], which gave optically active cyclic sulfa-
midate 2a in comparable yield and ee to those obtained
for the asymmetric intramolecular amidation of 1a with
PhI(OAc)2 catalyzed by the same ruthenium porphyrin.5a
We speculate that reaction of the in situ formed PhId
NSO2OR with [Ru(F20-TPP)(CO)] and [Ru(Por*)(CO)]
would afford the bis(imido)ruthenium(VI) species
[RuVI(Por)(NSO2OR)2] (Por ) F20-TPP, Por*), like the
reactions between [Ru(Por)(CO)] (Por ) TPP, OEP, Por*,
etc.) and PhIdNSO2-p-C6H4CH3 to give isolable [RuVI
(Por)(NSO2-p-C6H4CH3)2] in previous works.9e,h However,
attempts to isolate [RuVI(F20-TPP)(NSO2OR)2] and [RuVI
-
-
(Por*)(NSO2OR)2] from the foregoing [Ru(F20-TPP)(CO)]-
and [Ru(Por*)(CO)]-catalyzed intramolecular amidation
of 1a -n were not successful. This could be due to the
presence of reactive â- or γ-C-H bonds in the corre-
sponding imido groups, which cause degradation of the
imido species through, for example, intramolecular ami-
dation reactions.
Thus, we prepared PhIdNSO2OCH2CCl3 from reaction
of PhI(OAc)2 with the sulfamate ester Cl3CCH2OSO2NH2.
Interestingly, subsequent treatment of PhIdNSO2OCH2-
CCl3 with [Ru(F20-TPP)(CO)] according to a procedure
similar to that for preparation of [RuVI(TPP)(NSO2-p-
C6H4CH3)2]9e did give [RuVI(F20-TPP)(NSO2OCH2CCl3)2]
(Scheme 2), which was isolated in 60% yield and identi-
fied by 1H NMR, IR, UV-vis spectroscopy, and mass
spectrometry, together with elemental analyses (see the
Experimental Section). This is the first isolated metal
imido complex derived from a sulfamate ester, whose
formation signifies the intermediacy of bis(imido)ruthe-
nium(VI) porphyrins in the intramolecular amidation of
sulfamate esters with PhI(OAc)2 catalyzed by ruthenium
porphyrins.
F IGURE 2. Correlation between relative amidation rates (log
kR) and C-H bond dissociation energies (BDE) for the inter-
molecular amidation of hydrocarbons with “PhI(OAc)2 + NH2-
SO2-p-C6H4NO2” catalyzed by [Ru(F20-TPP)(CO)].
Our previous mechanistic studies9e on the inter-
molecular amidation of saturated C-H bonds by [RuVI
-
(TPP)(NSO2-p-C6H4CH3)2] supported a mechanism that
features hydrogen atom abstraction by the bis(imido)
complex to give a carboradical and an amido ruthenium
porphyrin intermediate. Scavenging of the carboradical
by the amido ruthenium porphyrin results in formation
of the amidation product.
Examination of the intermolecular amidation of a
variety of hydrocarbons, including 9,10-dihydroanthracene,
fluorene, cyclohexene, cumene, ethylbenzene, and tolu-
ene, with “PhI(OAc)2 + NH2SO2-p-C6H4NO2” catalyzed
by [Ru(F20-TPP)(CO)] revealed that the relative amida-
tion rates of these hydrocarbons (measured through
competitive amidation reactions, see the Experimental
Section) correlate with the C-H bond dissociation ener-
gies (Figure 2), like the C-H bond oxidations by [(bpy)2-
(9) For mechanistic studies on intermolecular C-N bond formation
reactions with PhIdNSO2R catalyzed by metal complexes, see: (a)
Mahy, J .-P.; Bedi, G.; Battioni, P.; Mansuy, D. J . Chem. Soc., Perkin
Trans. 2 1988, 1517. (b) Evans, D. A.; Faul, M. M.; Bilodeau, M. T. J .
Am. Chem. Soc. 1994, 116, 2742. (c) Li, Z.; Quan, R. W.; J acobsen, E.
N. J . Am. Chem. Soc. 1995, 117, 5889. (d) Na¨geli, I.; Baud, C.;
Bernardinelli, G.; J acquier, Y.; Moran, M.; Mu¨ller, P. Helv. Chim. Acta
1997, 80, 1087. (e) Au, S.-M.; Huang, J .-S.; Yu, W.-Y.; Fung, W.-H.;
Che, C.-M. J . Am. Chem. Soc. 1999, 121, 9120. (f) Brandt, P.;
Sodergren, M. J .; Andersson, P. G.; Norrby, P. O. J . Am. Chem. Soc.
2000, 122, 8013. (g) Gillespie, K. M.; Crust, E. J .; Deeth, R. J .; Scott,
P. Chem. Commun. 2001, 785. (h) Liang, J .-L.; Huang, J .-S.; Yu, X.-
Q.; Zhu, N.; Che, C.-M. Chem. Eur. J . 2002, 8, 1563.
(py)RuIVO]2+ 11
. This further supports the hydrogen atom
abstraction mechanism of the ruthenium porphyrin-
mediated intermolecular amidation reactions.
We propose that the intramolecular amidation of
sulfamate esters with PhI(OAc)2 catalyzed by ruthenium
porphyrins also occurs by hydrogen atom abstraction. To
gain further insight into the mechanism of such reac-
tions, we examined the reactions of racemic and enan-
tiopure sulfamate 3-methylpentyl ester (rac- and (S)-1p )
(10) (a) Stang, P. J .; Zhdankin, V. V. Chem. Rev. 1996, 96, 1123. (b)
Zhdankin, V. V.; Stang, P. J . Chem. Rev. 2002, 102, 2523.
(11) Bryant, J . R.; Mayer, J . M. J . Am. Chem. Soc. 2003, 125, 10351.
3614 J . Org. Chem., Vol. 69, No. 11, 2004

Intramolecular C-N Bond Formation Reactions
SCHEME 3. In tr a m olecu la r Am id a tion of
Su lfa m a te 3-Meth ylp en tyl Ester w ith P h I(OAc)2
Ca ta lyzed by [Ru (F 20-TP P )(CO)].
with PhI(OAc)2 in the presence of [Ru(F20-TPP)(CO)] and
Al2O3 under the same conditions as for 1g-o. These
reactions afforded the corresponding cyclic sulfamidate
2p in 72% yield (Scheme 3). For the amidation of (S)-1p ,
only a single enantiomer of 2p was detected, whose
absolute configuration is identical to that observed by
using catalyst [Rh2(CH3CO2)4], as revealed by the 1H
NMR spectra of the products in the presence of europium
tris(3-(heptafluoropropylhydroxymethylene)-(+)-camphor-
ate) (see Figure S1 in the Supporting Information). The
other enantiomer of 2p , if any, should account for <5%
of the total amount of the two enantiomers (estimated
from the sensitivity of the NMR instrument). Since the
intramolecular PhI(OAc)2-amidation of (S)-1p catalyzed
by [Rh2(CH3CO2)4] is stereospecific,4b the same intramo-
lecular amidation catalyzed by [Ru(F20-TPP)(CO)] should
occur in a similar manner with no or little racemization.
This could indicate that the carboradical species resulting
from the hydrogen atom abstraction in the ruthenium
porphyrin-catalyzed intramolecular amidation is too
short-lived to undergo configuration inversion. Alterna-
tively, one can consider the intramolecular amidation as
a concerted process. If such is the case, a nonsynchronous
concerted mechanism bearing significant hydrogen atom
abstraction character and involving short-lived or par-
tially developed carboradical species seems more reason-
able, given the fact that the intermolecular amidation
with “PhI(OAc)2 + NH2SO2-p-C6H4NO2” catalyzed by [Ru-
(F20-TPP)(CO)] most probably occurs by a hydrogen atom
abstraction.
Irrespective of whether the ruthenium porphyrin-
catalyzed intramolecular amidation of sulfamate esters
proceeds by a hydrogen atom abstraction or a concerted
mechanism, we could rationalize the virtually complete
cis-selectivity previously observed in the [Ru(F20-TPP)-
(CO)]-catalyzed intramolecular amidation of 1e,5a which
contrasts with a 8:1 (cis/trans) cis-selectivity in the
dirhodium-catalyzed counterpart.4b Figure 3a shows a
simplified model structure of the proposed imido inter-
mediate in the former intramolecular amidation system.
The positional parameters of the F20-TPP ligand and the
geometry of the Ru-N-S moieties were taken from the
X-ray crystal structure of bis(imido)osmium(VI) porphy-
rin [OsVI(F20-TPP)(NSO2-p-C6H4CH3)2].12 The geometry of
the imido groups was based on the model structure of
1e built in CS Chem3D Pro 4.0 with MM2 energy
minimization. Inspection of the model structure in Figure
3a by employing the Chem3D program revealed that the
C-Ha bond can well approach the imido nitrogen atom,
through a combination of internal rotations about the
C-C, C-O, O-S, and S-N bonds in the imido group, to
form a three-centered transition state, whereas the C-Hb
F IGURE 3. Simplified model structures of the proposed bis-
(imido) intermediates [RuVI(F20-TPP)(NSO2OR)2] in the in-
tramolecular PhI(OAc)2-amidation of (a) 1e and (b) 1a cata-
lyzed by [Ru(F20-TPP)(CO)]. Only one of the two imido groups
and key hydrogen atoms are shown. The fluoro substituents
on the meso-phenyl groups of F20-TPP are omitted for clarity.
bond always points away from the imido nitrogen atom
during any combinations of the internal rotations. This
could explain why the trans cyclic sulfamidate was not
obtained from the corresponding intramolecular amida-
tion.
Similar rationalization is also applicable for the virtu-
ally complete cis-selectivity in the intramolecular ami-
dation of 1a catalyzed by [Ru(F20-TPP)(CO)] or [Ru-
(Por*)(CO)] (see Figure 3b). The situation for 1f is
somewhat different. Modeling studies showed that the
benzylic C-H bond that results in trans cyclic sulfami-
date does not always point away from the imido nitrogen
atom during the internal rotations; however, the steric
interactions between the phenyl, cyclohexyl, and -OSO2
moieties prevent this C-H bond to closely approach the
nitrogen atom to reach the three-centered transition
state.
For substrate series 1m f 1n f 1o with [Ru(F20-TPP)-
(CO)] as a catalyst, we observed increased steric interac-
tion between the imido group and the F20-TPP meso-
pentafluorophenyl groups in the proposed imido inter-
mediates. In the case of 1o, the steric interaction between
the oxygen atom of the o-methoxy group and the benzylic
hydrogen atoms, coupled with the steric interaction
between the phenyl group and the porphyrin ligand,
renders it hard for the benzylic C-H bonds to approach
the imido nitrogen atom to reach the three-centered
transition state. This could account for the above-
mentioned decreased intramolecular amidation efficiency
along 1m f 1n and the ineffectiveness of catalyst [Ru-
J . Org. Chem, Vol. 69, No. 11, 2004 3615

Liang et al.
TABLE 4. In tr a m olecu la r Azir id in a tion of
2-Vin yl-ben zen esu lfon a m id e (3a ) w ith P h I(OAc)2
Ca ta lyzed by [Ru (F 20-TP P )(CO)]a
T (°C)
equiv of
(reaction conv yieldc
entry PhI(OAc)2 additiveb solvent time (h)) (%)
(%)
1
2
3
4
5
6
7
8
1.5
1.5
1.5
1.5
1.5
1.5
2
MgO
MgO
MgO
K2CO3
Al2O3
Al2O3
Al2O3
Al2O3
CH2Cl2 rt (12)
C6H6 rt (12)
90
72
18
95
93
92
98
82
61
68
10
54
63
68
53
54
CH3CN rt (12)
CH2Cl2 rt (12)
CH2Cl2 rt (12)
CH2Cl2 40 (3)
CH2Cl2 40 (3)
CH2Cl2 40 (3)
1.1
a
b
Catalyst loading: 2 mol % (relative to 3a ). 2.5 equiv. c Iso-
lated yield based on the amount of consumed substrate.
in Figure 4a and to the bulkier ethano-bridge in Figure
4b, thus leading to the observed preferential formation
of (1R,2S)-2a in the [Ru(Por*)(CO)]-catalyzed intramo-
lecular amidation of 1a .
F IGURE 4. Schematic structures of the key transition states
proposed for the asymmetric intramolecular PhI(OAc)2-ami-
dation of 1a catalyzed by [Ru(Por*)(CO)]. The transition states
in (a) and (b) result in formation of (1R,2S)-2a and (1S,2R)-
2a , respectively. Space-filling representations for these transi-
tion states are depicted in (c) for (a) and in (d) for (b). The
X-ray crystal structure of the predominant enantiomer in the
optically active 2a obtained from the [Ru(Por*)(CO)]-catalyzed
asymmetric intramolecular amidation of 1a is shown in (e).
For clarity, only one imido group and the norbornane moieties
at the same side as the imido group are shown. The key
hydrogen atoms are indicated in (a)-(d) to facilitate evaluation
of the configuration or steric hindrance.
In tr a m olecu la r Azir id in a tion of Un sa tu r a ted Su l-
fon a m id es Ca ta lyzed by Ru th en iu m P or p h yr in s.
Intramolecular aziridination of unsaturated sulfonamides
involving iodine(III) compounds catalyzed by metal com-
plexes is so far confined to dirhodium2b,5b,c and copper
catalysts.3a-c The lack of metalloporphyrin catalysts for
such transformation is somewhat surprising in view of
the well-documented intermolecular aziridination reac-
tions with PhIdNSO2R catalyzed by iron, manganese,13
and ruthenium porphyrins.6a,9h
Following our recent work on dirhodium-catalyzed
intramolecular aziridination of unsaturated sulfonamides
with PhI(OAc)2, which affords bicyclic aziridines in up
to 98% yield with up to 100% substrate conversion,5b,c
we studied the reaction between 2-vinylbenzenesulfona-
mide (3a ) and PhI(OAc)2 in the presence of 2 mol % of
[Ru(F20-TPP)(CO)] and observed formation of the corre-
sponding bicyclic aziridine (4a ). Table 4 shows the results
obtained for this reaction under various conditions.
As shown in Table 4, the [Ru(F20-TPP)(CO)]-catalyzed
intramolecular PhI(OAc)2-aziridination of 3a at room
temperature for 12 h, with MgO as an additive at a PhI-
(OAc)2/3a molar ratio of 1.5:1, resulted in 90% conversion
and 61% yield in dichloromethane (entry 1), a solvent
superior to benzene and acetonitrile for this reaction in
terms of substrate conversion (cf. entries 1-3). Changing
the additive to K2CO3 or Al2O3 increased the conversion
to 95 and 93%, respectively (entries 4 and 5), and Al2O3
is a better additive than K2CO3 in terms of product yield.
The reaction occurred more rapidly when the tempera-
ture was raised to 40 °C, with 92% conversion and 68%
yield obtained within 3 h (entry 6). However, increasing
and decreasing the PhI(OAc)2/3a molar ratio both led to
a significant drop in the yield of 4a (cf. entries 6-8).
A series of other unsaturated sulfonamides, 3b-h (see
Table 5), also underwent similar intramolecular aziridi-
nation. When the reactions were conducted in dichlo-
romethane at 40 °C for 3 h, with substrate/PhI(OAc)2/
(F20-TPP)(CO)] in catalyzing intramolecular amidation of
1o with PhI(OAc)2.
To rationalize the enantioselectivity in the asymmetric
intramolecular amidation reactions of 1a ,f-n , it is neces-
sary to know the absolute configuration of the predomi-
nant enantiomers of the optically active cyclic sulfami-
dates 2a ,f-n , which was found to be (1R,2S) for 2a by
X-ray crystal structure analysis5a (so far we have not been
able to determine such configurations in other cases). By
taking the positional parameters of Por* in the X-ray
crystal structure of [Ru(Por*)(CO)(L)],9h we built a model
structure for the proposed intermediate [RuVI(Por*)-
(NSO2O-indan-2-yl)2] in the same manner as for its F20
-
TPP analogue. Figure 4 shows the model structures of
the symmetric three-centered transition states typical for
the hydrogen atom abstraction mechanism (the unsym-
metric three-centered transition states typical for a
concerted mechanism are not shown, which result in a
similar rationalization to that described below). Exami-
nation of the model structures revealed that the transi-
tion state corresponding to (1R,2S)-2a (Figure 4a) en-
counters little steric interaction between the imido group
and the porphyrin ligand, whereas significant steric
interaction persists in the transition state corresponding
to (1S,2R)-2a (Figure 4b), as is evident from the space-
filling models depicted in parts c and d, respectively, of
Figure 4. This can be rationalized by the fact that the
imido phenyl group points to the smaller methano-bridge
3616 J . Org. Chem., Vol. 69, No. 11, 2004

Intramolecular C-N Bond Formation Reactions
TABLE 5. In tr a m olecu la r Azir id in a tion of Va r iou s
Un sa tu r a ted Su lfon a m id es w ith P h I(OAc)2 in th e
P r esen ce of Al2O3 Ca ta lyzed by [Ru (F 20-TP P )(CO)]a
yield of 5i from the [Ru(F20-TPP)(CO)]-catalyzed reaction
(55%, entry 8 in Table 5) is substantially lower than that
in the [Rh2(OAc)4]-catalyzed one (90%).5b
In an effort to develop an asymmetric version of the
intramolecular aziridination of sulfonamides, we exam-
ined the reaction between 3a and PhI(OAc)2 in the
presence of catalyst [Ru(Por*)(CO)] under the same
conditions as denoted in Table 5. This reaction resulted
in 43% conversion, affording 4a in 65% yield and 9% ee,
an enantioselectivity much lower than that in the [Ru-
(Por*)(CO)]-catalyzed intramolecular amidation of sulfa-
mate esters with PhI(OAc)2. Good enantioselectivity (up
to 76% ee) in asymmetric intramolecular aziridination
of sulfonamides with PhI(OAc)2 has been attained in our
recent work by employing chiral dirhodium catalysts.5c
Earlier, we found that [Ru(F20-TPP)(CO)] is a robust
catalyst for intramolecular amidation of saturated C-H
bonds, exhibiting up to >300 turnovers in PhI(OAc)2-
amidation of 1e to form 2e.5a Remarkably, when the [Ru-
(F20-TPP)(CO)]-catalyzed intramolecular aziridination of
3e was performed in dichloromethane at 40 °C for 36 h
at a low catalyst loading (catalyst/substrate/PhI(OAc)2/
Al2O3 molar ratio ) 1:5000:6500:12500), the cyclic aziri-
dine 4e was obtained in 53% yield with 76% conversion,
corresponding to a turnover number of 2014. This turn-
over number is substantially higher than those (up to
1375) observed for the intramolecular aziridination reac-
tions catalyzed by copper3a,c and dirhodium complexes.5b,c
entry substrate product
conversion (%)
yieldb (%)
1
2
3
4
5
6
7
8
3b
3c
3d
3e
3f
3g
3h
3i
4b
4c
4d
4e
100
90
95
88
85
100
100
100
87
73
87
82
79
4f
4g + 5g
4h + 5h
5i
28 (4g), 45 (5g)
41 (4h ), 25 (5h )
55
a
Reaction conditions: CH2Cl2, 40 °C, 3 h, catalyst/substrate/
PhI(OAc)2/Al2O3 molar ratio ) 0.02:1:1.5:2.5. b Isolated yield based
on the amount of consumed substrate.
Al2O3 molar ratio of 1:1.5:2.5, we obtained the corres-
ponding cyclic aziridines 4b-h in 28-87% yields with
85-100% conversions (entries 1-7, Table 5).
Con clu sion s
Ruthenium porphyrins are active catalysts for in-
tramolecular C-N bond formation reactions. The in-
tramolecular amidation of sulfamate esters with PhI-
(OAc)2 catalyzed by [Ru(F20-TPP)(CO)] and [Ru(Por*)(CO)]
affords cyclic sulfamidates with excellent diastereoselec-
tivity, good-to-high enantioselectivity (for the latter
catalyst), and is applicable to a wide variety of sulfamate
ester substrates. These ruthenium-catalyzed reactions
probably involve bis(imido)ruthenium(VI) porphyrin in-
termediates, whose conversion to cyclic sulfamidates
might occur by intramolecular hydrogen atom abstrac-
tion. The intramolecular aziridination of unsaturated
sulfonamides with PhI(OAc)2 catalyzed by [Ru(F20-TPP)-
(CO)] features good-to-high product yields with up to
complete substrate conversion and unprecedentedly high
turnovers, creating a precedent for efficient intramolecu-
lar aziridination catalyzed by metalloporphyrins.
The intramolecular aziridination of 3d catalyzed by
[Ru(F20-TPP)(CO)] resulted in 95% conversion with 87%
yield (entry 3, Table 5); both are higher than those
catalyzed by dirhodium complexes (up to 81 and 74%,
respectively).5b,c For substrates 3a -c,e,f, the correspond-
ing products 4a -c,e,f were obtained in 68-87% yields
(entry 6 in Table 4 and entries 1, 2, 4, and 5 in Table 5),
which are lower than those observed for the dirhodium-
catalyzed counterparts (80-97%).5b,c
Unsaturated sulfonamides 3g,h have allylic or benzylic
C-H bonds that could undergo intramolecular amidation
to form five-membered cyclic sulfonamides 5g,h in a
manner analogous to that of metal-catalyzed intramo-
lecular amidation of sulfamate esters containing â-C-H
bonds.4b,5a However, such intramolecular amidation of
3g,h has not been observed by employing copper3a,c and
dirhodium catalysts.5b,c It is surprising that, in the
presence of catalyst [Ru(F20-TPP)(CO)], the reactions
between 3g,h with PhI(OAc)2 gave 5g,h in 45 and 25%
yields, respectively, with the intramolecular aziridination
products formed in 28 (4g) and 41% (4h ) yields. While
Exp er im en ta l Section
P r ep a r a tion of Su lfa m a te Ester s 1g-o. These com-
pounds were prepared from respective alcohols according to a
procedure similar to that reported by Du Bois and co-workers.4b
this indicates a decreased selectivity of catalyst [Ru(F20
-
1
1g. H NMR (CDCl3, 300 MHz): δ ) 7.28 (m, 2H), 7.16 (m,
TPP)(CO)] for the intramolecular aziridination of 3g,h ,
it reflects a higher catalytic activity of the ruthenium
porphyrin for intramolecular amidation of related sul-
fonamides.
2H), 4.77 (s, 2H), 4.37 (t, J ) 6.8 Hz, 2H), 3.02 (t, J ) 6.8 Hz,
2H). 13C NMR (CDCl3, 75 MHz): δ ) 135.3, 133.3, 130.7, 129.2,
71.4, 34.9. HRMS: calcd for C8H10ClNO3S 235.0070, found
235.0067.
1
1h . H NMR (CDCl3, 400 MHz): δ ) 7.12 (m, 4H), 4.66 (s,
For unsaturated sulfonamide 3i (see Table 5), whose
allylic C-H bonds could be amidated intramolecularly
to give six-membered cyclic sulfonamide 5i, no intramo-
lecular aziridination product was obtained; the product
identified was 5i. This is similar to the analogous copper-
2H), 4.37 (t, J ) 7.0 Hz, 2H), 3.01 (t, J ) 7.0 Hz, 2H); 2.32 (s,
3H). 13C NMR (CDCl3, 100 MHz): δ ) 137.0, 133.7, 129.7,
129.9, 72.0, 35.2, 21.4. HRMS: calcd for C9H13NO3S 215.0616,
found 215.0615.
1
1i. H NMR (CDCl3, 300 MHz): δ ) 7.14 (m, 2H), 6.85 (m,
3a,c
or dirhodium-catalyzed5b,c reactions, except that the
2H), 4.62 (s, 2H), 4.36 (t, J ) 7.0 Hz, 2H), 3.79 (s, 3H), 2.99 (t,
J . Org. Chem, Vol. 69, No. 11, 2004 3617

Liang et al.
J ) 7.0 Hz, 2H). 13C NMR (CDCl3, 75 MHz): δ ) 158.6, 130.0,
128.4, 114.1, 71.8, 55.3, 34.4. HRMS: calcd for C9H13NO4S
231.0565, found 231.0560.
128.5, 115.1, 75.5, 59.7, 55.9. HRMS: calcd for C9H11NO4S
229.0409, found 229.0406.
2j. H NMR (CDCl3, 300 MHz): δ ) 7.88 (m, 4H), 7.51 (m,
1
1
1j. H NMR (CDCl3, 400 MHz): δ ) 7.81 (m, 3H), 7.69 (s,
3H), 5.26 (m, 1H), 4.91 (t, J ) 8.6 Hz, 1H), 4.82 (m, 1H), 4.55
(t, J ) 8.6 Hz, 1H). 13C NMR (CDCl3, 100 MHz): δ ) 134.0,
133.5, 132.9, 130.1, 128.4, 128.2, 127.5, 127.4, 126.8, 123.7,
75.1, 60.2. HRMS: calcd for C12H11NO3S 249.0460, found
249.0454.
1H), 7.47 (m, 2H), 7.32 (d, J ) 8.1 Hz, 1H), 4.63 (s, 2H), 4.49
(t, J ) 6.9 Hz, 2H), 3.21 (t, J ) 6.9 Hz, 2H). 13C NMR (CDCl3,
100 MHz): δ ) 134.2, 133.8, 132.8, 128.7, 128.0, 127.9, 127.8,
127.4, 126.7, 126.2, 71.8, 35.8. HRMS: calcd for C12H13NO3S
251.0616, found 251.0601.
1
2k . H NMR (CDCl3, 300 MHz): δ ) 7.92 (m, 3H), 7.76 (d,
1k . 1H NMR (CDCl3, 300 MHz): δ ) 8.01 (d, J ) 7.4 Hz,
1H), 7.88 (d, J ) 7.8 Hz, 1H), 7.77(m, 1H), 7.53 (m, 2H), 7.41
(m, 2H), 4.53 (m, 4H), 3.54 (t, J ) 7.3 Hz, 2H). 13C NMR
(CDCl3, 75 MHz): δ ) 134.2, 132.1, 129.4, 128.3, 127.7, 126.8,
J ) 7.2 Hz, 1H), 7.58 (m, 3H), 5.84 (m, 1H), 5.06 (m, 1H), 4.93
(d, J ) 6.7 Hz, 1H), 4.59 (t, J ) 8.0 Hz, 1H). 13C NMR (CDCl3,
75 MHz): δ ) 133.9, 130.8, 130.3, 129.9, 129.4, 127.3, 126.4,
125.6, 123.9, 123.8, 74.3, 56.4. HRMS: calcd for C12H11NO3S
249.0460, found 249.0460.
126.2, 125.9, 123.5, 118.5, 71.1, 32.7. HRMS: calcd for C12H13
-
NO3S 251.0616, found 251.0616.
1
2l. H NMR (CDCl3, 400 MHz): δ ) 7.34 (m, 2H), 7.10 (m,
1
1l. H NMR (CDCl3, 400 MHz): δ ) 7.14 (m, 2H), 6.98 (m,
2H), 4.89 (s, 2H), 4.20 (t, J ) 6.3 Hz, 2H), 2.72 (t, J ) 7.4 Hz,
2H), 2.04 (m, 2H). 13C NMR (CDCl3, 100 MHz): δ ) 161.6 (d,
J C-F ) 242.5 Hz), 136.0, 129.8, 115.3, 70.3, 30.7, 30.4. HRMS:
calcd for C9H12FNO3S 233.0522, found 233.0517.
2H), 4.85 (m, 2H), 4.65 (m, 1H), 4.35 (d, J ) 9.3 Hz, 1H), 2.22
(m, 1H), 2.01 (m, 1H). 13C NMR (CDCl3, 100 MHz): δ ) 162.8
(d, J C-F ) 247.0 Hz), 133.8, 128.4, 116.1, 71.7, 58.3, 30.1.
HRMS: calcd for C9H10FNO3S 231.0365, found 231.0365.
2m . 1H NMR (CDCl3, 300 MHz): δ ) 7.27 (m, 2H), 6.91 (m,
2H), 4.81 (m, 2H), 4.65 (m, 1H), 4.25 (d, J ) 9.3 Hz, 1H), 3.81
(s, 3H), 2.25 (m, 1H), 1.99 (m, 1H). 13C NMR (CDCl3, 75
MHz): δ ) 159.9, 130.1, 127.6, 114.5, 71.8, 58.4, 55.3, 30.1.
HRMS: calcd for C10H13NO4S 243.0565, found 243.0567.
1m . 1H NMR (CDCl3, 400 MHz): δ ) 7.11 (m, 2H), 6.83 (m,
2H), 4.82 (s, 2H), 4.19 (t, J ) 6.3 Hz, 2H), 3.79 (s, 3H), 2.69 (t,
J ) 7.3 Hz, 2H), 2.04 (m, 2H). 13C NMR (CDCl3, 100 MHz): δ
) 158.1, 132.4, 129.4, 114.0, 70.5, 55.3, 30.6, 30.5. HRMS:
calcd for C10H15NO4S 245.0722, found 245.0720.
1
2n . H NMR (CDCl3, 300 MHz): δ ) 7.32 (m, 1H), 6.91 (m,
1n . 1H NMR (CDCl3, 400 MHz): δ ) 7.21 (t, J ) 7.4 Hz,
1H), 6.76 (m, 3H), 4.75 (s, 2H), 4.09 (t, J ) 6.6 Hz, 2H), 3.80
(s, 3H), 2.67 (t, J ) 8.0 Hz, 2H), 1.96 (m, 2H). 13C NMR (CDCl3,
100 MHz): δ ) 159.8, 142.0, 129.5, 120.9, 114.4, 111.5, 70.5,
55.2, 31.6, 30.2. HRMS: calcd for C10H15NO4S 245.0722, found
245.0723.
3H), 4.85 (m, 2H), 4.67 (m, 1H), 4.32 (d, J ) 9.3 Hz, 1H), 3.82
(s, 3H), 2.23 (m, 1H), 2.04 (m, 1H). 13C NMR (CDCl3, 100
MHz): δ ) 160.2, 139.5, 130.2, 118.2, 114.3, 112.1, 71.8, 58.8,
55.4, 30.2. HRMS: calcd for C10H13NO4S 243.0565, found
243.0571.
Typ ica l P r oced u r e for Com p etitive In tr a m olecu la r
Am id a tion of pa r a -Su bstitu ted Su lfa m a te Ester p-X-
C6H4(CH2)2OSO2NH2 (X ) MeO, Me, Cl, Br ) vs C6H5-
(CH2)2OSO2NH2 Ca ta lyzed by [Ru (F 20-TP P )(CO)]. To a
mixture of p-X-C6H4(CH2)2OSO2NH2 (1 mmol), C6H5(CH2)2-
OSO2NH2 (1 mmol), [Ru(F20-TPP)(CO)] (0.015 mmol), and
Al2O3 (0.6 mmol) in dichloromethane (10 mL) was added PhI-
(OAc)2 (0.5 mmol). The mixture was stirred at room temper-
ature under argon for 3 h, followed by filtration through Celite.
Chromatography on silica gel with dichloromethane as eluent
gave a mixture of two cyclic sulfamidate products (correspond-
ing to the intramolecular amidation of p-X-C6H4(CH2)2OSO2-
NH2 and C6H5(CH2)2OSO2NH2, respectively). The molar ratio
of these two products was determined by 1H NMR and was
taken as the relative rate kX/kH.
Typ ica l P r oced u r e for Com p etitive In ter m olecu la r
Am id a tion of Hyd r oca r bon s w ith “P h I(OAc)2 + NH2SO2-
p-C6H4NO2” Ca ta lyzed by [Ru (F 20-TP P )(CO)]. PhI(OAc)2
(0.5 mmol) was added to a dichloromethane solution containing
ethylbenzene (1 mmol), another hydrocarbon (1 mmol), NH2-
SO2-p-C6H4NO2 (0.5 mmol), 1,4-dichlorobenzene (1 mmol) (as
the internal standard), and [Ru(F20-TPP)(CO)] (0.02 mmol).
The reaction mixture was stirred at room temperature for 3
h. The amounts of ethylbenzene and the other hydrocarbon
before and after the reaction were determined by GC. The ratio
between the consumed moles of the other hydrocarbon and
ethylbenzene was taken as the relative rate kR.
1
1o. H NMR (CDCl3, 400 MHz): δ ) 7.21 (m, 1H), 7.12 (d,
J ) 7.3 Hz, 1H), 6.87 (m, 2H), 4.89 (s, 2H), 4.20 (t, J ) 6.4 Hz,
2H), 3.81 (s, 3H), 2.73 (t, J ) 7.3 Hz, 2H), 2.03 (m, 2H). 13C
NMR (CDCl3, 100 MHz): δ ) 157.8, 130.4, 129.2, 127.9, 120.8,
110.8, 71.5, 55.6, 29.0, 26.7. HRMS: calcd for C10H15NO4S
245.0722, found 245.0721.
Typ ica l P r oced u r e for In tr a m olecu la r Am id a tion of
Su lfam ate Ester s Catalyzed by [Ru (F 20-TP P )(CO)]. Dichlo-
romethane (1.5 mL) was added via syringe into a Schlenk flask
containing sulfamate ester (0.18 mmol), PhI(OAc)2 (0.36
mmol), catalyst (0.0027), Al2O3 (0.45 mmol), and molecular
sieves (4 Å, 50 mg) under an argon atmosphere. The mixture
was stirred at 40 °C for 2 h, diluted with dichloromethane (5
mL) after cooling to room temperature, and filtered through
Celite. The residue on Celite was washed with dichloro-
methane (2 × 5 mL). Evaporation of the combined filtrates
under reduced pressure followed by chromatography on silica
gel column with dichloromethane as eluent afforded cyclic
sulfamidate as a white solid.
Typ ica l P r oced u r e for Asym m etr ic In tr a m olecu la r
Am id a tion of Su lfa m a te Ester s Ca ta lyzed by [Ru (P or *)-
(CO)]. This procedure is the same as that for catalyst [Ru-
(F20-TPP)(CO)] except that 0.25 mmol of PhI(OAc)2 and 0.018
mmol of catalyst [Ru(Por*)(CO)] (rather than [Ru(F20-TPP)-
(CO)]) was used and the reaction was conducted in benzene
at 5 °C for 8 h.
1
2g. H NMR (CDCl3, 300 MHz): δ ) 7.38 (m, 4H), 5.06 (m,
Typ ica l P r oced u r e for In tr a m olecu la r Azir id in a tion
1H), 4.89 (d, J ) 5.7 Hz, 1H), 4.84 (t, J ) 7.0 Hz, 1H), 4.40 (t,
J ) 8.4 Hz, 1H). 13C NMR (CDCl3, 75 MHz): δ ) 135.9, 134.5,
130.0, 128.4, 74.9, 59.3. HRMS: calcd for C8H8ClNO3S 232.9913,
found 232.9922.
of Un sa tu r a ted Su lfon a m id es Ca ta lyzed by [Ru (F 20
-
TP P )(CO)]. This procedure is the same as that for the [Ru-
(F20-TPP)(CO)]-catalyzed intramolecular amidation of sulfa-
mate esters except that 0.2 mmol of unsaturated sulfonamide
(instead of sulfamate ester), 0.3 mmol of PhI(OAc)2, 0.004
mmol of catalyst, and 0.5 mmol of Al2O3 were used, and the
mixture was stirred for 3 h (affording cyclic sulfonamide rather
than sulfamidate).
1
2h . H NMR (CDCl3, 300 MHz): δ ) 7.26 (m, 4H), 5.05 (m,
1H), 4.81 (m, 1H), 4.70 (d, J ) 6.2 Hz, 1H), 4.44 (t, J ) 8.8
Hz, 1H), 2.37 (s, 3H). 13C NMR (CDCl3, 75 MHz): δ ) 139.7,
132.1, 130.1, 126.6, 75.1, 59.5, 21.1. HRMS: calcd for C9H11
NO3S 213.0460, found 213.0453.
-
1
5g. H NMR (CDCl3, 300 MHz): δ ) 5.86 (m, 1H), 5.32 (m,
2i. 1H NMR (CDCl3, 400 MHz): δ ) 7.34 (d, J ) 8.6 Hz,
2H), 6.94 (d, J ) 8.5 Hz, 2H), 5.02 (m, 1H), 4.78 (t, J ) 6.8
Hz, 1H), 4.69 (d, J ) 6.4 Hz, 1H), 4.44 (t, J ) 8.7 Hz, 1H),
3.82 (s, 3H). 13C NMR (CDCl3, 100 MHz): δ ) 160.9, 129.4,
2H), 4.21 (s, 1H), 4.16 (t, J ) 6.7 Hz, 1H), 3.18 (m, 2H), 2.58
(m, 1H), 2.23 (m, 1H). 13C NMR (CDCl3, 75 MHz): δ ) 136.8,
117.9, 57.2, 47.6, 29.9. HRMS: calcd for C5H9NO2S 147.0354,
found 147.0347.
3618 J . Org. Chem., Vol. 69, No. 11, 2004

Intramolecular C-N Bond Formation Reactions
5h . 1H NMR (CDCl3, 300 MHz): δ ) 7.80 (d, J ) 7.4 Hz,
1H), 7.64 (t, J ) 7.6 Hz, 1H), 7.56 (t, J ) 7.6 Hz, 1H), 7.36 (d,
J ) 7.6 Hz, 1H), 5.85 (m, 1H), 5.56 (d, J ) 16.9 Hz, 1H), 5.41
(d, J ) 9.9 Hz, 1H), 5.14 (m, 1H), 4.80 (s, 1H). 13C NMR (CDCl3,
75 MHz): δ ) 159.2, 138.7, 135.4, 133.6, 130.0, 125.3, 121.7,
120.5, 60.6. HRMS: calcd for C9H9NO2S 195.0354, found
195.0344.
P r ep a r a tion of P h IdNSO2OCH2CCl3. This compound
was prepared from reaction of PhI(OAc)2 with CCl3CH2OSO2-
NH2 in the presence of KOH according to the procedure
reported by Dodd and Dauban for preparation of PhId
NSO2(CH2)2SiMe3.14 1H NMR (CD3OD, 300 MHz): δ ) 8.05
(d, J ) 7.8 Hz, 2H), 7.60 (m, 3H), 4.57 (s, 2H). 13C NMR (CDCl3,
75 MHz): δ ) 137.8, 135.3, 130.6, 127.8, 78.9, 78.8. HRMS:
calcd for C8H7Cl3INO3S 428.8257, found 428.8245.
under argon for 5 min. The mixture was then evaporated to
dryness in vacuo followed by chromatography on a short
column of neutral alumina (active grade II) with dichloro-
methane as eluent. The first red band was collected and the
solvent was removed in vacuo. Recrystallization from dichlo-
romethane-hexane afforded the desired product in 60% yield.
1H NMR (300 MHz, CDCl3): δ ) 9.14 (s, 8H), 1.26 (s, 4H). IR
(KBr pellet, cm-1): 1022 (“oxidation state marker” band9e).
UV-vis (CH2Cl2) λmax (log ꢀ) ) 409 (5.21), 527 (4.19). ESI MS:
m/z 1526 (M+). Anal. Calcd for C48H12Cl6F20N6O6S2Ru‚
3C6H14: C, 44.41; H, 3.05; N, 4.71. Found: C, 44.64; H, 2.43;
N, 4.40.
Ack n ow led gm en t. This work was supported by The
University Development Fund of The University of
Hong Kong and the University Grants Committee of the
Hong Kong SAR of China (Area of Excellent Scheme,
AoE/P-10/01).
Syn t h esis of Bis(im id o)r u t h en iu m (VI) P or p h yr in
[Ru VI(F 20-TP P )(NSO2OCH2CCl3)2]. A mixture of [Ru(F20
-
TPP)(CO)] (0.05 mmol) and PhIdNSO2OCH2CCl3 (0.2 mmol)
in dichloromethane (8 mL) was stirred at room temperature
Su p p or tin g In for m a tion Ava ila ble: General experimen-
tal methods, Figure S1, 13C NMR spectra of 1g-o, 2g-n , 5g,h ,
and PhIdNSO2OCH2CCl3, and HPLC spectra of racemic and
optically active 2g-n . This material is available free of charge
via the Internet at http://pubs.acs.org.
(12) Li, Y.; Huang, J .-S.; Zhou, Z.-Y.; Che, C.-M. J . Am. Chem. Soc.
2001, 123, 4843.
(13) (a) Mansuy, D.; Mahy, J .-P.; Dureault, A.; Bedi, G.; Battioni,
P. J . Chem. Soc., Chem. Commun. 1984, 1161. (b) Mahy, J .-P.; Bedi,
G.; Battioni, P.; Mansuy, D. J . Chem. Soc., Perkin Trans. 2 1988, 1517.
(14) Dauban, P.; Dodd, R. H. J . Org. Chem. 1999, 64, 5304.
J O0358877
J . Org. Chem, Vol. 69, No. 11, 2004 3619