Page 261 - Arrow Pushing in Inorganic Chemistry A Logical Approach to the Chemistry of the Main Group Elements

6.15 SULFUR NITRIDES 241
An examination of the starting materials and the products strongly suggests that
[(Me Si) N] S provides a key part of the structural framework for S N , whereas SCl 2
4
2
3
2
4
provides the rest of the structural sulfur. Armed with that insight, it’s reasonable to deploy
the amine nitrogens in nucleophilic attacks on SCl :
2
Me Si SiMe 3 Me Si
3
Me 3 Si S SiMe 3 S SiMe 3
N N 3 Me Si N SiMe 3 −
3
Cl + N + Cl
(6.119)
S S
Cl
Cl
The chloride anion produced then carries out a nucleophilic displacement on one of the silyl
groups, producing trimethylsilyl chloride in the process:
−
Cl Cl
Me Si SiMe 3 −
3
Me 3 Si S SiMe SiMe 3 S SiMe 3
SiMe
N N 3 SiMe 3 N 3
+ + N
S S
Cl Cl (6.120)
SiMe 3
SiMe 3 S
− Me 3 SiCl N
N
S SiMe 3
Cl

An intramolecular nucleophilic displacement, followed by chloride-mediated desilylation,
leads to the formation of a bis(trimethylsilyl)-S N ring:
2
2
−
Cl
Me 3 Si
Me 3 Si
Me 3 Si S Me 3 Si
N N + N S
S SiMe 3 S N
Cl SiMe 3
Cl
−
Me 3 Si Me Si
3
Me 3 Si N S
N S − Me SiCl
3
+
S N S N
SiMe
SiMe 3 3
(6.121)