A mild and highly chemoselective iodination of alcohol using polymer supported DMAP

Article abstract of DOI:10.1007/s12039-016-1158-1

The synthesis of organic compounds using polymer supported catalysts and reagents, where the required product is always in solution, has been of great interest in recent years, both in industries and academia especially in pharmaceutical research. Here, a simple and efficient method for conversion of alcohols into their iodides in high yield using polymer supported 4-(Dimethylamino)pyridine (DMAP) is described. Polymer supported DMAP is used in catalytic amount and is recovered and reused several times. Additionally, this method is highly chemoselective. [Figure not available: see fulltext.]

Full text of DOI:10.1007/s12039-016-1158-1

c
J. Chem. Sci. ꢀ Indian Academy of Sciences.
DOI 10.1007/s12039-016-1158-1
A mild and highly chemoselective iodination of alcohol using polymer
supported DMAP
DIPARJUN DASa, JASHA MOMO H ANALb and LALTHAZUALA ROKHUMa,∗
aDepartment of Chemistry, National Institute of Technology, Silchar, Assam 788 010, India
bDepartment of Chemistry, North Eastern Hill University, Shillong, Meghalaya 793 022, India
e-mail: lalthazualarokhum@gmail.com
MS received 9 January 2016; revised 14 July 2016; accepted 13 August 2016
Abstract. The synthesis of organic compounds using polymer supported catalysts and reagents, where the
required product is always in solution, has been of great interest in recent years, both in industries and academia
especially in pharmaceutical research. Here, a simple and efficient method for conversion of alcohols into
their iodides in high yield using polymer supported 4-(Dimethylamino)pyridine (DMAP) is described. Polymer
supported DMAP is used in catalytic amount and is recovered and reused several times. Additionally, this
method is highly chemoselective.
Keywords. Iodination; Polymer supported DMAP; Triphenylphosphine; Iodine; Catalyst; Chemoselective.
1. Introduction
2. Experimental
Organo-iodides are widely used in carbon-carbon cou- 2.1 Materials and Methods
pling reactions and as intermediates for organic syn-
thesis in substitution,1 elimination and rearrangement
reactions.2 Presently, organo-iodides are of great use in
medical field as well.3,4 Many methods for conversion
of alcohol to iodide have already been reported in lite-
rature5 10 but they have a number of drawbacks like high
temperature,11 long reaction times,12 tedious work-up
procedures,13 use of excess reagents,14 low yields, dras-
tic conditions, and presence of hazardous vapours.15
Development of polymer supported catalysts for or-
ganic transformation is one of the important features in
organic synthesis because it is reusable and easily sepa-
rated from the reaction system.16 In recent years, the
environmental concerns associated with their toxicity,
disposal and catalyst/product separation are limiting
the applications of homogeneous catalyst in organic
syntheses. Therefore, polymer supported catalysts are
becoming increasingly important in organic synthesis,
primarily due to their low moisture susceptibility, easy
handling, minimum side reactions, easy recyclability and
reusability. Unlike commonly used acid-base catalysts,
polymer supported catalysts offer easy recovery of the
catalyst by simple filtration, thereby reducing opera-
tional cost.
All the chemicals were used without further purifi-
cation. All alcohols were of analytical grade. Poly-
mer supported DMAP (4-(Dimethylamino)pyridine,
polymer-supported: ∼3.0 mmol/g, crosslinked with 2%
DVB)waspurchasedfromSigmaAldrichandiodinewas
bought from SpectroChem. Solvents used were extra
pure grade purchased from Merck India and were dried
by the reported procedure. All compounds were identi-
fied by comparing their spectroscopic data with known
samples. 1H NMR and 13C NMR spectra of the iodides
were performed on Bruker Avance II 400 MHz FT
NMR and Bruker Avance III, 500 MHz FT NMR
Spectrometer using CDCl3 as solvent.
2.2 General procedure for the iodination of alcohols
To a stirred solution of triphenylphosphine (1.5 mmol)
in dry dichloromethane was added iodine (1.5 mmol)
and polymer supported 4-DMAP (0.4 mmol, 40 mol%).
Stirring was continued for 2 min; alcohol (1mmol) was
then added. The reaction was monitored by TLC. After
complete conversion of the alcohol (as indicated by
TLC), the reaction was quenched with an aqueous solu-
tion of sodium thiosulfate (20 mL). The organic solvents
were removed and the aqueous solution extracted with
ethylacetate (50 mL). The combined organic layers were
dried using sodium sulfate (anhydrous), filtered and
∗For correspondence

Diparjun Das et al.
concentrated. The residue was purified by column chro- (d, J = 6.8 Hz, 2H), 7.10 (d, J = 7.2 Hz, 2H), 4.06
matography (2% EtOAc in hexane) to get the desired (s,2H), 3.76 (s, 3H); 13C-NMR (100 MHz, CDCl3,
iodide product.
TMS): δ 153.90, 129.45, 128.30, 114.00, 56.84, 10.92;
IR (KBr): ν 3022, 2915, 1591, 1478, 1284, 1221, 1127,
811, 710 cm−1; HRMS: m/z 247.9693 (M+); Elemental
analysis for C8H9IO: Calculated (%); C 38.74, H 3.66;
Found (%): C 38.76, H 3.64.
2.3 Selected spectral data
2.3a Benzyl iodide (Table 2, Entry 1): Yellow crys-
talline solid, M.p.: 22–23◦C, (litt.9,17h M.p. 21–23◦C),
1H-NMR (500 MHz, CDCl3, TMS): δ 7.34 (d, J = 4.8
Hz, 2H), 7.27 (t, J = 4.8 Hz, 2H), 7.20 (t, J = 2.68 Hz,
1H), 4.42 (s, 2H); 13C-NMR (100 MHz, CDCl3, TMS):
δ 139.34, 128.89, 128.82, 127.95, 77.47, 76.04, 5.94;
IR (KBr): ν 2917, 1589, 1147, 1050, 830, 639 cm−1;
HRMS: m/z 217.9590 (M+); Elemental analysis for
C7H7I: Calculated (%); C 38.56, H 3.24; Found(%): C
38.55, H 3.25.
2.3f (2-Iodoethyl)benzene (Table 2, Entry 10): Yel-
low liquid, (litt.17h), 1H-NMR (400 MHz, CDCl3,
TMS): δ 7.22 (m, 3H), 7.16 (t, J = 6.8 Hz, 2H), 3.30
(t, J = 8 Hz, 2H), 3.13 (t, J = 7.6 Hz, 2H). 13C-NMR
(100 MHz, CDCl3, TMS): δ 140.67, 128.49, 128.08,
127.14, 126.92, 126.59, 40.40, 5.80; IR (KBr): ν 3029,
2975, 2856, 1904, 1571, 1503, 1483, 1198, 1137, 832,
691 cm−1; HRMS: m/z 231.9746 (M+); Elemental anal-
ysis for C8H9I: Calculated (%); C 41.41, H 3.91; Found
(%): C 41.42, H 3.90.
2.3b 4-Methyl benzyl iodide (Table 2, Entry 2): Pale
yellow liquid, (litt.17h), H-NMR (400 MHz, CDCl3,
1
TMS): δ 7.85 (d, J = 8 Hz, 2H), 6.76 (d, J = 8 Hz, 2H),
4.14 (s, 2H), 2.40 (S, 3H); 13C-NMR (100 MHz, CDCl3,
TMS): δ 137.81, 136.28, 129.54, 128.63, 21.25, 6.22;
IR (KBr): ν 3020, 2920, 1590, 1455, 1148, 1049, 832,
641 cm−1; HRMS: m/z 231.9748 (M+); Elemental anal-
ysis for C8H9I: Calculated (%): C 41.41, H 3.91; Found
(%): C 41.43, H 3.89.
2.3g 1-Iodooctane (Table 2, Entry 15): Colorless
1
liquid, (litt.17h), H-NMR (400 MHz, CDCl3, TMS): δ
3.17 (t, J = 6.8 Hz, 2H), 1.78 (m, 2H), 1.36 (t, J = 6.4
Hz, 2H), 1.27 (s, 4H), 0.865 (t, J = 6.8 Hz, 3H). 13C-
NMR (100 MHz, CDCl3, TMS): δ 33.57, 30.52, 29.71,
29.10, 28.52, 22.64, 14.10, 7.39; IR (KBr): ν 2421,
1822, 1573, 1454, 1214, 944, 913, 863, 712, 452 cm−1;
HRMS: m/z 240.0376 (M+); Elemental analysis for
C8H17I: Calculated (%); C 40.02, H 7.14; Found (%): C
40.01, H 7.15.
2.3c 4-Chlorobenzyl iodide (Table 2, Entry 3): Col-
orless crystalline solid, M.p.: 58–59◦C (litt.9,17h M.p.
1
58–60◦C), H-NMR (500 MHz, CDCl3, TMS): δ 7.92
(d, J = 8 Hz, 2H), 7.22 (d, J = 8.4 Hz, 2H), 4.29(s, 2H);
13C-NMR (125 Hz, CDCl3, TMS): δ 137.87, 133.62,
129.48, 128.29, 4.19; IR (KBr): ν 3010, 2915, 1605,
1505, 1490, 1410, 1205, 1150, 1080, 825, 665 cm−1;
HRMS: m/z 251.9203 (M+); Elemental analysis for
C7H6ClI: Calculated (%): C 33.30, H 2.41; Found (%):
C 33.28, H 2.39.
2.3h 1-Iodododecane (Table 2, Entry 16): Colorless
1
liquid, (litt.17h), H-NMR (500 MHz, CDCl3, TMS): δ
3.18 (t, J = 10 Hz, 2H), 1.81 (q, J = 10 Hz, 2H), 1.55
(s, 2H), 1.38(m, J = 5 Hz, 10H), 0.87 (t, J = 5 Hz,
3H); 13C-NMR (125 Hz, CDCl3, TMS): δ 33.59, 31.91,
30.52, 29.70, 29.62, 29.55, 29.43, 29.34, 28.55, 22.69,
14.13, 7.36; IR (KBr): ν 2422, 1812, 1577, 1455, 1217,
947, 915, 865, 710, 458 cm−1; HRMS: m/z 296.1003
(M+); Elemental analysis for C12H25I: Calculated (%);
C 48.65, H 8.51; Found (%): C 48.64, H 8.49.
2.3d 4-Bromobenzyl iodide (Table 2, Entry 5): Crys-
talline white solid, M.p.: 58–59◦C (litt.11,17h M.p. 57–
1
59◦C), H-NMR (500 MHz, CDCl3, TMS): δ 7.43 (d,
J = 3.5 Hz, 2H), 7.10 (d, J = 4.5 Hz, 2H), 4.41 (s, 2H);
13C-NMR (125 Hz, CDCl3, TMS): δ 138.39, 132.01,
130.42, 121.78, 4.46; IR (KBr): ν 3015, 2893, 1600,
1510, 1475, 1398, 1212, 1131, 1067, 776, 651, 532,
469 cm−1; HRMS: m/z 295.8693 (M+); Elemental anal-
ysis for C7H6BrI: Calculated (%); C 28.31, H 2.04;
Found (%): C 28.31, H 2.06.
2.3i 1-Iodooctadecane (Table 2, Entry 17): White
1
crystalline solid, M.p.: 34–35◦C, H-NMR (400 MHz,
CDCl3, TMS): δ 3.09 (t, J = 7.04 Hz, 2H), 1.748
(m, 2H), 1.31 (m, 2H), 1.19 (m, 24H), 0.81 (t, J =
6.6 Hz, 3H); 13C-NMR (100 MHz, CDCl3, TMS): δ
33.66, 32.01, 30.61, 29.65, 29.46, 28.65, 22.77, 14.20,
7.01; IR (KBr): ν 2912, 2817, 1438, 1376, 983, 846,
2.3e 4-Methoxybenzyl iodide (Table 2, Entry 9): 752, 683 cm−1; HRMS: m/z 380.1938 (M+); Elemental
Pale yellow solid, M.p.: 25–26◦C, (litt.9,17h M.p. 25– analysis for C18H37I: Calculated (%); C 56.83, H 9.80;
1
27◦C), H-NMR (400 MHz, CDCl3, TMS): δ 7.20 Found (%): C 56.84, H 9.79.

Iodination of alcohols
2.3j Citronellyl iodide (Table 2, Entry 19): Colorless (400 MHz, CDCl3, TMS): δ 7.92 (d, J = 7.6 Hz, 2H),
1
liquid, (litt.17h), H-NMR (400 MHz, CDCl3, TMS): 7.21(d, J = 7.6 Hz, 2H), 3.82 (t, J = 7.2 Hz, 2H),
δ 5.07 (t, J = 6.8 Hz, 1H), 3.21 (m, 2H), 1.85 (m, 3.06 (t, J = 7.2 Hz, 2H); 13C-NMR (100 MHz, CDCl3,
2H), 1.68 (s, 3H), 1.60 (s, 3H), 1.53 (m, 2H), 1.29 TMS): δ 143.40, 132.09, 132.00, 115.34, 40.36, 31.91;
(m, 2H), 1.14 (m, 1H), 0.87 (d, J = 6.4 Hz, 3H); HRMS: m/z 261.8990 (M+); Elemental analysis for
13C-NMR (100 MHz, CDCl3, TMS): δ 131.45, 124.47, C8H8Br2: Calculated (%); C 36.40, H 3.06; Found (%):
40.92, 36.33, 33.58, 25.75, 25.33, 18.67, 17.71, 5.14; C 36.42, H 3.04.
IR (KBr): ν 2931, 2411, 1513, 1423, 1353, 1278, 994,
766, 701 cm−1; HRMS: m/z 266.0530 (M+); Elemental
analysis for C10H19I: Calculated (%); C 45.13, H 7.20;
3. Results and Discussion
Found (%): C 45.14, H 7.19.
In continuation of our on-going interest for the devel-
opment of useful synthetic methodologies,17 herein,
2.3k Iodocyclohexane (Table 2, Entry 21): Light
we have reported the synthesis of organo-halide com-
pounds using catalytic amount of polymer supported
yellow semi liquid, (litt.17h), 1H-NMR (400 MHz,
CDCl3, TMS): δ 4.27 (m, 1H), 2.15 (d, J = 9.6 Hz, 2H)
DMAP, 1. Iodination of alcohols to its correspond-
2.00 (d, J = 14.4 Hz, 2H), 1.92 (t, J = 12.8 Hz, 2H),
ing iodides was achieved using triphenylphosphine
and iodine reagent system with excess base which is
assumed to neutralize the hydroiodic acid generated in
1.60 (t, J = 20 Hz, 2H), 1.39 (d, J = 8 Hz, 2H); 13C-
NMR (100 MHz, CDCl3, TMS): δ 39.60, 32.85, 27.32,
the reaction.12,14 But Hajipour and co-workers11 have
shown that the conversion could be achieved with-
out the reaction system being neutral. This finding
prompted us to investigate the iodination reaction using
catalytic amount of base (Scheme 1).
25.20; IR (KBr): ν 2419, 1820, 1575, 1455, 1224, 954,
916, 865, 715, 455 cm−1; HRMS: m/z 209.9907 (M+);
Elemental analysis for C6H11I: Calculated (%); C 34.31,
H 5.28; Found (%): C 34.33, H 5.26.
2.3l 1-Bromo-4-(2-bromoethyl)benzene (Table 2,
To achieve this, iodination of benzyl alcohol was
Entry 28): White crystalline solid, M.p.: 95–96◦C, carried out at room temperature by changing different
parameters as given in Table 1. Among the various
solvents tried, dichloromethane was found to be the
best solvent for the transformation (Table 1, entry 4).
After optimising the solvents, our next obvious target
Scheme 1. Iodination of alcohols.
Scheme 2. Chemoselective iodination.
Table 1. Optimization of reaction conditionsa.
Entry
Mol% of catalyst 1 used
Solvent
Time (h)
Conversion (%)
1.
2.
3.
4.
5.
6.
7.
8.
9.
40
10
20
40
–
50
40
40
50
CH3CN
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
EtOAc
CHCl3
THF
2
3
2
1
3
2
2
3
3
51
31
82
Quantitative
12
61
84
71
45
Toluene
aReaction condition: alcohol (1 mmol), PPh3 (1.5 mmol), iodine (1.5 mmol), solvent,
room temperature.

Diparjun Das et al.
Table 2. Iodination of alcohol with polymer supported DMAPa.
Entry
Alcohol
Product
Time(h)
1
% Yieldb
95
1.
2.
1
1.5
2
92
94
89
90
87
96
91
97
88
90
3.
4.
5.
1.5
1.5
2
6.
7.
8.
2
9.
1
10.
11.
1.5
1.5
12.
13.
14.
15.
2
3
1
1
92
87
92
95

Iodination of alcohols
Table 2. (continued)
Entry
Alcohol
Product
Time(h)
1.5
% Yieldb
89
16.
17.
18.
19.
20.
1.5
1.2
1
86
90
95
90
1
21.
22.
3
3
89
0
23
12
84
87
24.
3
25.
26.
27.
28.
3.5
4
84
89
2
91c
90c
2
aReaction condition: alcohol (1 mmol), PPh3 (1.5 mmol), iodine (1.5 mmol) DMAP (0.4 mmol, 40 mol%), DCM, room
temperature. bIsolated yield. cBromine (Br2) were used in place of iodine.

Diparjun Das et al.
Table 3. Chemoselective iodination of alcohol with polymer supported DMAPa.
Entry
Alcohol
Product
Time(h)
1
% Yieldb
92
1.
2.
3.
4.
5.
1.5
1
89c
92
94
92
1
1.5
6.
7.
1
3
89
89
aReaction condition: alcohol (1 mmol), PPh3 (1.5 mmol), iodine (1.5 mmol), DMAP (0.4 mmol, 40 mol%), DCM, room
temperature. bIsolated yield. cBromine was used in place of iodine.
is to optimize the amount of base catalyst and reagents even after prolonged stirring (Table 2, entry 22). To our
required. At the outset, different quantities of catalyst pleasure, tertiary alcohols were also successfully con-
and reagents were investigated and we found that use verted to their corresponding iodides (Table 2, entries
of 40 mol% DMAP, 1 with molar ratio of 1.5:1.5:1 for 25–26). After exploring the iodination of varieties of
triphenylphosphine/iodine/alcohol gave optimum yield. alcohols, we turned our attention towards the possibil-
With the optimized reaction condition in our hand, ity of direct bromination using bromine (Br2) under our
we examined a variety of primary, secondary, tertiary optimized reaction condition used for iodination. Grati-
and benzylic alcohols carrying electron-donating and fyingly, we found that the bromination of alcohols also
electron withdrawing groups to determine the scope of occurred equally well giving the desired bromides in
this procedure. The results are given in Table 2. The high yields (Table 2, entries 27–28).
results for the iodination under our optimized condi-
Chemoselective iodination of unsymmetrical diols
tions were, in general, good to excellent. Thus, when was also carried out under our optimized reaction con-
benzyl alcohol (Table 2, entry 1) and short aliphatic ditions (Scheme 2). Our system works well for the
alcohols were used (Table 2, entries 14–15), the cor- selective iodination of a variety of unsymmetrical diols
responding iodides were obtained in excellent yield. in favour of the less hindered alcohols (Table 3). It has
However, when longer aliphatic chains were used, been observed that primary alcohol moiety solely
lower yields were observed (Table 2, entries 16–18). It undergoes iodination discriminating the secondary
was observed that, substrates with electron withdraw- alcohol. Hence, butane-1,3-diol exclusively gave 4-
ing group in the benzene ring took maximum time iodobutan-2-ol in 92% yield (Table 3, entry 1). Chemos-
(Table 2, entries 7–8) whereas electron-donating sub- elective iodination of 2-methylpentane-2,4-diol to yield
stituent group reduced the time for complete consump- 4-iodo-2-methylpentan-2-ol was also successfully car-
tion of the starting alcohol (Table 2, entry 9). Secondary ried out showing complete selectivity of our protocol
alcohols required longer reaction time for complete (Table 3, entry 7).
conversion compared to their primary counterparts
Recovery and reusability of the catalyst are very
(Table 2, entry 1 vs. 12). However, the conversion of important factors for practical application of the het-
phenol into its corresponding iodide was not successful erogeneous system. The reusability of the catalyst was

Iodination of alcohols
azides S Patai and Z J Rappoport (Eds.) (New York:
also investigated using benzyl alcohol as a test substrate
using our optimized reaction conditions. After comple-
tion of the first set of reaction (run 1) to afford the
corresponding product in 95% yield within 1 hour, the
catalyst was recovered by simply washing with ethyl
acetate and drying it at 100◦C in Abderhalden apparatus
under reduced pressure. A new reaction was then per-
formed with fresh solvent and reactants under the same
condition. To our satisfaction, catalyst could be reused
at least four times without any noticeable change in
activity (run 2, 3 and 4 gave 95%, 93% and 92% yield,
respectively).
Wiley) p.1353
3. Abraham G E and Flechas J E 2007 The Original
Internist 15 8
4. Arroyo-Helguera O, Rojas E, Delgado G and Aceves C
2008 Endocr. Relat. Cancer 15 1003
5. Hajipour A R, Mostafavi M and Ruoho A E 2009 Org.
Prep. Proced. Int. 41 87
6. Jung M E and Ornstein P L 1977 Tetrahedron. Lett. 31
2659
7. Martinez A G, Alvarez R M, Vilar E T, Fraile A G,
Barnica J O, Hanack M and Subramanian L R 1987
Tetrahedron Lett. 28 6441
8. Firouzabadi H, Iranpoor N and Jafarpour M 2004 Tetra-
hedron Lett. 45 7451
9. Hayat S, Atta-ur-Rahman, Khan K M, Choudhary M I,
Maharvi G M, Zia-Ullah and Bayer E 2003 Synth.
Commun. 33 2531
4. Conclusions
10. Firouzabadi H, Iranpoor N and Ebrahimzadeh F 2006
Tetrahedron Lett. 47 1171
11. Hajipour A R, Falahati A R and Ruoho A E 2006
Tetrahedron Lett. 47 4191
12. (a) Garegg P J and Samuelsson G J 1979 J. Chem. Soc.,
Chem. Commun. 978; (b) Garegg P J, Johansson R,
Ortega C and Samuelsson G J 1982 Chem. Soc., Perkin
Trans. 1 681
In conclusion, we have developed an efficient and
highly chemoselective method of iodination under very
mild condition by using triphenylphosphine, iodine and
catalytic amount of polymer supported 4-DMAP. The
catalyst could be regenerated very easily and reused
several times without loss in efficiency, thus making the
reaction cost effective and environmentally benign.
13. Tundo
952
P and Venturello P 1979 Synthesis 12
Supporting information (SI)
14. (a) Anilkumar G, Nambu H and Kita Y 2002 Org.
Proc. Res. Dev. 6 190; (b) Rokhum L, Vanlalveni C and
Lalfakzuala R 2013 IJETCAS 13 370
Spectral data (1H NMR and 13C NMR) are available as
Supplementary Information at www.ias.ac.in/chemsci.
15. Appel
R 1975 Angew. Chem. Int. Ed. Engl.
14 801
16. (a) Hodge P 2005 Ind. Eng. Chem. Res. 44 8542;
(b) Gladysz J A 2002 Chem. Rev. 103 3216; (c)
McNamara C A, Dixon M J and Bradley M 2002
Chem. Rev. 102 3275; (d) Sandaroos R, Goldani M T,
Damavandi S and Mohammadi A 2012 J. Chem. Sci. 124
871; (e) Islam N S and Boruah J J 2015 J. Chem. Sci.
127 777
Acknowledgements
We gratefully acknowledge Science and Engineering
Research Board (SERB)-DST, Govt. of India, New
Delhi for financial supports [sanctioned no: SB/FT/CS-
103/2013, SB/EMEQ-076/2014].
17. (a) Pathak G and Rokhum L 2015 ACS Comb. Sci.
17 483;
(b) Rokhum L and Bez 2013 Can. J. Chem.
References
91 300; (c) Rokhum L and Bez G 2013 Tetrahedron
Lett. 54 5500; (d) Rokhum L and Bez G 2011 J.
Chem. Sci. 124 687; (e) Bora P P, Vanlaldinpuia K,
Rokhum L and Bez G 2011 Synth. Commun. 41 2674; (f)
Rokhum L and Bez G 2011 Synth. Commun. 41 548; (g)
Vanlaldinpuia K, Sema H A, Rokhum L and Bez G 2010
Chem. Lett. 39 228; (h) Das D, Chanda T and Rokhum
L 2015 Acta Chim. Slov. 62 775
1. (a) Frisch A C and Beller M 2005 Angew. Chem. Int. Ed.
44 674; (b) Su M D and Chu S Y 1999 J. Am. Chem.
Soc. 121 1045
2. Naso F and Marchese G 1983 In Carbon–carbon bond
formation involving organic halides and transition metal
compounds. The Chemistry halides, pseudo-halides and