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The reactions of trimethyl(methylthio)- and trialkyl(arylthio)stannanes with alkyl halides
161
Journal of Organometallic Chemistry. 149 (1978) 161-165 0 E%evier Sequoia Sk, Lausanne - Printed in The Netherlands
THE REACTIONS OF TRIMETHYL(METHYLTHIO)AND TRIALKYL(ARYLTHIO)STANNANES WITH ALKYL HALIDES
SEXZI KOZUKA
* and SADAMU
OHYA
Department of Applied Chemistry, Faculty of Engineering. Osaka City University, Sugimotocho, Sumiyoshi-ku. Osaka 558 (Japan) (Received
July 19th,
1977)
Summary The reaction of trimethyl(methyIthio)stannane with methyl iodide was reinvestigated. Trimethylsulfonium iodide and iodotrimethylstannane were the products which were isolated. Trialkylhalostannanes and alkyl aryl sulfides were obtained in nearly quantitative yield by the reaction of trialkyl(arylthio)starmanes with alkyl halides. The rate of the reaction of the trialkyl(arylthio)stannanes with an a&y1 iodide was much slower than that of trimethyl(methy!thio)stannane under the same reaction conditions. Nucleophilic attack of the stannyl sulfur atom on the alkyl halide is suggested as the first step of the reaction. Few reactions of the organotin-u&r linkage with alkyl halides have been reported [l-3]. We have reinvestigated the reaction of trimethyl(methylthio)stannane with methyl iodide. The reactions of arylthiostannane with alkyl halides also were examined in order to obtain a better understanding of the
chemical reactivity of the tin-sulfur bond. Both reactions have been found to proceed in similar manner. The reactions of trimethyl(methylthio)s”r;annane The reaction of organotin alkanethiolates of the type R,Sn(SR’)? with an excess of methyl iodide is known to give diorganotin diiodides (eq. 1) [l]. A similar reaction has been reported to occur with R3SnSR’ compounds (eq. 2) [ 11.
R$n(SMe),
w
R,SnI, f 2 Me,ST-
(1)
R=Me,EtandBu Bu,SnSMe 3
Bu,SnI
f Me&-
(2)
162.
:._..
..
.:.
.' ..
-
:
b $&se reactio& proceed with fi~ssion~ofthe tin-sulfur bond. A~notable. excep -tion .is t&erea@i&i of tr&nethyl(methylthio)stxnnane with _tiequimolar &mount of methyl iodide, which was reported‘togive the sulfonium salt without the cleavage ofthe Sri--- bond (eq. 3) [2]. It inay be that the retention of the Sn-S
Me,SnSMe + Me1 + Me,SnS’Me,
I-
(3)
(1) bond is due to the different reaction conditions used. Thus, the reaction with an equimolar amount of methyl iodide may result in formation of the sulfonium salt I as the initial product, and anexcess of methyl iodide then serves to decompose this species, giving the iodostannane and dimethyl~sulfide. The latter then is converted further td trimethylsulfonium iodide. In order to clarify this possibility, we have repeated the reaction shown in eq. 3.lrimethy1(methy1thio)s tannane was warmed at 50°C for 3.5 h with an equimolar amount of methyl iodide in a sealed tube. The solids formed were collected and identified as trimethylsulfonium iodide (30% yield) rather than I*. The structure of the product was contkmed by comparison of the physical properties with those of an authentic sample prepared from dimethyl sulfide and. methyf iodide. The reaction was carried out under different reaction conditions in attempts to obtain the salt I, but only trimethylsulfonium iodide was obtained. The same product was obtained in 85% yield by the reaction with two equivalents of methyl iodide with the methylthiostannane at 80°C for 40 min. The reaction in chloroform solution with an excess of methyl iodide gave the same product, and PlMR analysis of the reaction solution showed that iodotrimethylstannane was the only chloroform-soluble product. The only evidence cited by Abel et al. in support of their salt I formulation was the elemental analysis for carbon and hydrogen. However, the postulated product and timethylsulfoniuin iodide have very similar carbon and hydrogen values **. We conclude that the product of Abel et al. was trimethylsulfonium iodide. The
reactionsof
triakyl(arylthio)stes
To date, only one reaction of an arylthiostannane with an alkyl halide has been reported: the reaction of t&akis(p-N,N-dimethylaminophenylthio)stannane with an excess of methyl iodide (eq. 4) [3]. However, no reaction has
~W6Ha~e2)4
B
SnI, + 4[(Me,NC,H,SMe)‘T]
.
(4)
been reported to occur between tri-n-butyl(phenylthio)stannane and methyl iodide Cl]. We have tried the reaction again and found a result similar to that observed with the methylthiostannane.
d” an eQuimOlat mixture of Me~nS?de (14.5 & * Abel et aL C21 O&Y mentioned that they “w0.069 mol) and Me1 (9.8 g. 0.069 mol) and that they obtained Me$SnS%e2T (15.0 g.6295). cOm&on the tin compound. 3ng the product as Me&l-. t%e maximum yield shouId be 60% wd ** Caled. for Me3SI: C. 17.7: EL 4.4%; for MegSnSMe21: C. 1.7-O; H,4.3%: Found by Abel et al-. C. 17.5: H. 5.2% [21.
P.CH~C~H~ C6HS C6H5 C6H5 C6H5 C6HS c6IIS
0.1 0,7 0.7 007 0.7 a,7 0.7 0,7 0,7 9.7 0.7 G.6 0.7 0.7 4,3
0.7
mm01
r&I
C2H5I C2HsBr bC3&I C6H,$H2Br C&CH2Br ~.CHJC~H&II~CI CH3i
CH3I CH3I CH3I
cI131
CH31 CH31 CH31 CH3I
R”X -.----.-
R”X
AND ARYLTHIO)STANNANES
0.7 1.4 1.4 7.0 7.0 7.0 7.0 7.9 7.0 7.0 7,o 0.7 17 0.7 7.0 32
-
_
_ _
- ._
none none none CHC13 CHCl3 CHCl3 CHC13 CHC13 CHCl3 CHCl3 CHCl3 CHC13 none CHCl3 CHCl3 none
Solvent a
HALIDES
GO 90 SO 7B 120 120 100 100 120 120 X20 120 100 120 90 100
9.97 0,67 2,o 1B 15 40 40 16 20 20 20 10 40 40 20
3,B
01)
(“C) .._-_*_-._
Time
Temp.
26d
b b 89”
76 8Ge
72 8G 94 64 100 74 100 b
b
b
R$nX
Yield (%)
300 EGO 28d 84C 89 98 07 88 74 100 69d 99 530 1oof 100 67C
R’SR”
.
-. -
reactton, converslon was not determined. c Isolated by dlstillntlon, fIncomplete
mm01 _-._.-__--._._“__-
WITH ALKYL
a 1 ml, bNot annlyzcd. C(CI~3)3S*I’,dinlethyl sulfldc wns not detected. d Incomplete reaction, ytcld was obtained bnsed on GG% convorslon.
CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CII3 n-C4Hg n-C4Hg
P-NDzC6H4 C61.15
CH3 CH3 C6Hs CH3 C6H5 PCH3C6H4 p.CIC6H4
CH3
CH3 CH3 CH3
R’
OF TRIALKYL(ALKYLTHI0
R
R3SnSR’
REACTION
TABLE 1
c&l &I a &.&$~s&&r td that. oft the methylthiostannane~ but differ in the rela.i+~e:~+ivities &$ in me sulfur-containing product isolated. The alkyl aryl sulfides did not bdeygol &ulfb@q& salt for&&on. These-&f&tic& can & explained in terms of the l&r &Ieophilicity of the a$thiO group. Th&, nucleophili& attack of the sulfur atom on the carbon atom &f the alkyl halid.eis the most plausibIe mechanism of the reaction. RsSnSR’ + R”%-
~[R,Sn~~~R”
X-1 ras?.R,SnX + R’-S-R”
R’ when R’-= alkylr
R’-S-R”
R”X R’R”,S+ X-
~e&lental Materials ‘I?ialkyl(aU@hib and. arylthio)stannanes were prepared from trialkylhalostannane and the appropri$e thiol [43. The reaction of ttimethyl(m~thyltkio)stannane with methyl iodide Using the proqedtie of Ab&l et al_-[Z], the stamzane (145 mg, 0.69 mmol) was w&x&d with tiethy1 iodide (98 mg, 0.69 mmol) in a sealed tube at 50°C for 3.5 h_ The solids which formed were ;collected and washed with hexane. The physic@ properties of the solids were identical to those of authentic trimethylsulfotium iodide and the yield was 30%, based on the tin compound used. Warmtig t&z reaction mixture at 5C$ fqr 1 h’gave the same product in 17% yield. The reaction .tith two eolar tiounts of methyl iodide at 80°C for 40 min gave trimethylsulfonium iodide in 85% yield. Iodotrimethylsta&me was detected by PB&Ranalysis of the reaction solution in chloroform-when an excess of methyl iodide we used. The resti& e shown in Table 1.. .!Che reg.&ion of frialkyl(arylfhio)st4nntlne with olkyl halide Trime~yl(phenyltbio)stzuin&e (0.7 mmol) and a lo-fold excess of methyl i&id& in CIICl~ (I&) were heated at 120°C fbr 15 h. Subsequently, dic$l&o.tiethan& (40 &) +as:_+++and. the *hole solution was -subject&l _to PMR analysis. Yields of i&iotri@&&$a&tie-(6 0.88 ppti) and &-ethyl phenyl sulfide
165 .
(6(C&), kk3 ppm).were determined by integration of l$e signals relative to that &thi)added &_chloromethane. No oth&r signal was detected in the clear reaction ‘s&tio$_ C&z rkactions were carried out similarly. The products were isolated by GLC (5%30,9O”C) knd the structures were identified by IR and PMR analysee Some r&actions were carried out on a preparative scale and the products were isolated by distillation. Reaction conditions and the yields of the products are gives in Table 1. References 1 2 3 4
C-1. Balcombe. E.C.Macullinand M.E. Peach. J. Inorg. NucL Chem., 37 (1975) 1353. ET.W.Abel and D.B. Brady. J. Chek. Sot.. (1966) 1192. I-L Wuyts and A. Vangindertaelen, BulL Sot. Chem. Belg., 30 (1921) 323. J-L. Wazdell
and D-W.
Grant. J. Or&za.nometa.L Chem..
20 (1969)
91.
Journal of Organometallic Chemistry. 149 (1978) 161-165 0 E%evier Sequoia Sk, Lausanne - Printed in The Netherlands
THE REACTIONS OF TRIMETHYL(METHYLTHIO)AND TRIALKYL(ARYLTHIO)STANNANES WITH ALKYL HALIDES
SEXZI KOZUKA
* and SADAMU
OHYA
Department of Applied Chemistry, Faculty of Engineering. Osaka City University, Sugimotocho, Sumiyoshi-ku. Osaka 558 (Japan) (Received
July 19th,
1977)
Summary The reaction of trimethyl(methyIthio)stannane with methyl iodide was reinvestigated. Trimethylsulfonium iodide and iodotrimethylstannane were the products which were isolated. Trialkylhalostannanes and alkyl aryl sulfides were obtained in nearly quantitative yield by the reaction of trialkyl(arylthio)starmanes with alkyl halides. The rate of the reaction of the trialkyl(arylthio)stannanes with an a&y1 iodide was much slower than that of trimethyl(methy!thio)stannane under the same reaction conditions. Nucleophilic attack of the stannyl sulfur atom on the alkyl halide is suggested as the first step of the reaction. Few reactions of the organotin-u&r linkage with alkyl halides have been reported [l-3]. We have reinvestigated the reaction of trimethyl(methylthio)stannane with methyl iodide. The reactions of arylthiostannane with alkyl halides also were examined in order to obtain a better understanding of the
chemical reactivity of the tin-sulfur bond. Both reactions have been found to proceed in similar manner. The reactions of trimethyl(methylthio)s”r;annane The reaction of organotin alkanethiolates of the type R,Sn(SR’)? with an excess of methyl iodide is known to give diorganotin diiodides (eq. 1) [l]. A similar reaction has been reported to occur with R3SnSR’ compounds (eq. 2) [ 11.
R$n(SMe),
w
R,SnI, f 2 Me,ST-
(1)
R=Me,EtandBu Bu,SnSMe 3
Bu,SnI
f Me&-
(2)
162.
:._..
..
.:.
.' ..
-
:
b $&se reactio& proceed with fi~ssion~ofthe tin-sulfur bond. A~notable. excep -tion .is t&erea@i&i of tr&nethyl(methylthio)stxnnane with _tiequimolar &mount of methyl iodide, which was reported‘togive the sulfonium salt without the cleavage ofthe Sri--- bond (eq. 3) [2]. It inay be that the retention of the Sn-S
Me,SnSMe + Me1 + Me,SnS’Me,
I-
(3)
(1) bond is due to the different reaction conditions used. Thus, the reaction with an equimolar amount of methyl iodide may result in formation of the sulfonium salt I as the initial product, and anexcess of methyl iodide then serves to decompose this species, giving the iodostannane and dimethyl~sulfide. The latter then is converted further td trimethylsulfonium iodide. In order to clarify this possibility, we have repeated the reaction shown in eq. 3.lrimethy1(methy1thio)s tannane was warmed at 50°C for 3.5 h with an equimolar amount of methyl iodide in a sealed tube. The solids formed were collected and identified as trimethylsulfonium iodide (30% yield) rather than I*. The structure of the product was contkmed by comparison of the physical properties with those of an authentic sample prepared from dimethyl sulfide and. methyf iodide. The reaction was carried out under different reaction conditions in attempts to obtain the salt I, but only trimethylsulfonium iodide was obtained. The same product was obtained in 85% yield by the reaction with two equivalents of methyl iodide with the methylthiostannane at 80°C for 40 min. The reaction in chloroform solution with an excess of methyl iodide gave the same product, and PlMR analysis of the reaction solution showed that iodotrimethylstannane was the only chloroform-soluble product. The only evidence cited by Abel et al. in support of their salt I formulation was the elemental analysis for carbon and hydrogen. However, the postulated product and timethylsulfoniuin iodide have very similar carbon and hydrogen values **. We conclude that the product of Abel et al. was trimethylsulfonium iodide. The
reactionsof
triakyl(arylthio)stes
To date, only one reaction of an arylthiostannane with an alkyl halide has been reported: the reaction of t&akis(p-N,N-dimethylaminophenylthio)stannane with an excess of methyl iodide (eq. 4) [3]. However, no reaction has
~W6Ha~e2)4
B
SnI, + 4[(Me,NC,H,SMe)‘T]
.
(4)
been reported to occur between tri-n-butyl(phenylthio)stannane and methyl iodide Cl]. We have tried the reaction again and found a result similar to that observed with the methylthiostannane.
d” an eQuimOlat mixture of Me~nS?de (14.5 & * Abel et aL C21 O&Y mentioned that they “w0.069 mol) and Me1 (9.8 g. 0.069 mol) and that they obtained Me$SnS%e2T (15.0 g.6295). cOm&on the tin compound. 3ng the product as Me&l-. t%e maximum yield shouId be 60% wd ** Caled. for Me3SI: C. 17.7: EL 4.4%; for MegSnSMe21: C. 1.7-O; H,4.3%: Found by Abel et al-. C. 17.5: H. 5.2% [21.
P.CH~C~H~ C6HS C6H5 C6H5 C6H5 C6HS c6IIS
0.1 0,7 0.7 007 0.7 a,7 0.7 0,7 0,7 9.7 0.7 G.6 0.7 0.7 4,3
0.7
mm01
r&I
C2H5I C2HsBr bC3&I C6H,$H2Br C&CH2Br ~.CHJC~H&II~CI CH3i
CH3I CH3I CH3I
cI131
CH31 CH31 CH31 CH3I
R”X -.----.-
R”X
AND ARYLTHIO)STANNANES
0.7 1.4 1.4 7.0 7.0 7.0 7.0 7.9 7.0 7.0 7,o 0.7 17 0.7 7.0 32
-
_
_ _
- ._
none none none CHC13 CHCl3 CHCl3 CHC13 CHC13 CHCl3 CHCl3 CHCl3 CHC13 none CHCl3 CHCl3 none
Solvent a
HALIDES
GO 90 SO 7B 120 120 100 100 120 120 X20 120 100 120 90 100
9.97 0,67 2,o 1B 15 40 40 16 20 20 20 10 40 40 20
3,B
01)
(“C) .._-_*_-._
Time
Temp.
26d
b b 89”
76 8Ge
72 8G 94 64 100 74 100 b
b
b
R$nX
Yield (%)
300 EGO 28d 84C 89 98 07 88 74 100 69d 99 530 1oof 100 67C
R’SR”
.
-. -
reactton, converslon was not determined. c Isolated by dlstillntlon, fIncomplete
mm01 _-._.-__--._._“__-
WITH ALKYL
a 1 ml, bNot annlyzcd. C(CI~3)3S*I’,dinlethyl sulfldc wns not detected. d Incomplete reaction, ytcld was obtained bnsed on GG% convorslon.
CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CII3 n-C4Hg n-C4Hg
P-NDzC6H4 C61.15
CH3 CH3 C6Hs CH3 C6H5 PCH3C6H4 p.CIC6H4
CH3
CH3 CH3 CH3
R’
OF TRIALKYL(ALKYLTHI0
R
R3SnSR’
REACTION
TABLE 1
c&l &I a &.&$~s&&r td that. oft the methylthiostannane~ but differ in the rela.i+~e:~+ivities &$ in me sulfur-containing product isolated. The alkyl aryl sulfides did not bdeygol &ulfb@q& salt for&&on. These-&f&tic& can & explained in terms of the l&r &Ieophilicity of the a$thiO group. Th&, nucleophili& attack of the sulfur atom on the carbon atom &f the alkyl halid.eis the most plausibIe mechanism of the reaction. RsSnSR’ + R”%-
~[R,Sn~~~R”
X-1 ras?.R,SnX + R’-S-R”
R’ when R’-= alkylr
R’-S-R”
R”X R’R”,S+ X-
~e&lental Materials ‘I?ialkyl(aU@hib and. arylthio)stannanes were prepared from trialkylhalostannane and the appropri$e thiol [43. The reaction of ttimethyl(m~thyltkio)stannane with methyl iodide Using the proqedtie of Ab&l et al_-[Z], the stamzane (145 mg, 0.69 mmol) was w&x&d with tiethy1 iodide (98 mg, 0.69 mmol) in a sealed tube at 50°C for 3.5 h_ The solids which formed were ;collected and washed with hexane. The physic@ properties of the solids were identical to those of authentic trimethylsulfotium iodide and the yield was 30%, based on the tin compound used. Warmtig t&z reaction mixture at 5C$ fqr 1 h’gave the same product in 17% yield. The reaction .tith two eolar tiounts of methyl iodide at 80°C for 40 min gave trimethylsulfonium iodide in 85% yield. Iodotrimethylsta&me was detected by PB&Ranalysis of the reaction solution in chloroform-when an excess of methyl iodide we used. The resti& e shown in Table 1.. .!Che reg.&ion of frialkyl(arylfhio)st4nntlne with olkyl halide Trime~yl(phenyltbio)stzuin&e (0.7 mmol) and a lo-fold excess of methyl i&id& in CIICl~ (I&) were heated at 120°C fbr 15 h. Subsequently, dic$l&o.tiethan& (40 &) +as:_+++and. the *hole solution was -subject&l _to PMR analysis. Yields of i&iotri@&&$a&tie-(6 0.88 ppti) and &-ethyl phenyl sulfide
165 .
(6(C&), kk3 ppm).were determined by integration of l$e signals relative to that &thi)added &_chloromethane. No oth&r signal was detected in the clear reaction ‘s&tio$_ C&z rkactions were carried out similarly. The products were isolated by GLC (5%30,9O”C) knd the structures were identified by IR and PMR analysee Some r&actions were carried out on a preparative scale and the products were isolated by distillation. Reaction conditions and the yields of the products are gives in Table 1. References 1 2 3 4
C-1. Balcombe. E.C.Macullinand M.E. Peach. J. Inorg. NucL Chem., 37 (1975) 1353. ET.W.Abel and D.B. Brady. J. Chek. Sot.. (1966) 1192. I-L Wuyts and A. Vangindertaelen, BulL Sot. Chem. Belg., 30 (1921) 323. J-L. Wazdell
and D-W.
Grant. J. Or&za.nometa.L Chem..
20 (1969)
91.