Tetrahedron Letters No.18, ppO 1421-1423,
1969. Pergamon Press.
Printed in Great Britain.
REACTIONS OF GROUP IV ORGANOMETALLIC COMPOUNDS
A NOVEL SYNTHESIS OF SUBSTITUTED CHLOROFORMAMIDINES OR GU~,NIDINr: BY THE REACTION OF ORGANOSILYLAMINES AND ISOCYANIDF~ICHLORII>E
Synthetic Chemistry, Faculty of Engineering,
(Received in Japan 12 February
Furo-cho, Chikusa-ku, Nagoya,
1969;received in lK for publication 10 March 1969)
Several addition reactions of organosilylsmines to unsaturated compounds* or cyclic compounds3'5 were extensively studied during these few years. In this publication, reactions between trimethylsilylamines and phenylisocyanidedichloride(&) are reported, which occur at 85O
for 24 hours and
afford chloroformamidines(H) in excellent yield through expulsion of trimethylchlorosilane.
included reaction conditions, yield of products, and physical
properties of chlorofonnamidines, which were identified by elementary analysis, infra-red, and nmr
This reaction would offer a convinient method
for the preparation of substituted chloroformamidines.
Chloroformamidines(P) by the Reaction of & with Trimethylsilyldialkylamines
B.p. of &
was treated with further one mole of trimethylsilylamine,
N-phenyl-N',N',N",N''-tetramethylguanidine (E) was obtained in 98.55;in the together with
case of R=CH3
could be prepared from the reaction between similarly.
2:l mole ratio of
We3SiNMe2 and &
N-Phenyl-N',N',N",N''-tetrsmethylguanidine (III) was identified
as picrate ( m.p. 157', Calcd. for
C17HzON607 ; C, 48.57, H, 4.80.
C, 48.36, H, 4.32). NKe2
850 Me3Si-NMe2 ----------+ 24 hrs.
/ Ph-N=C \
Me SiCl 3
However, similar reaction did not proceed in the case of trimethylsilyldiethyl-
di-n-propylamine, probably because of steric hindrance of
dialkylamino group. In the reaction of N-methylhexamethyldisilazane with I , the anticipated chloroformamidine(2)
could never be isolated and the products obtained were
and trimethylchlorosilane (43>")which suggested
subsequent P-elimination of IV
as eq. 3.
Cl I+ Ph-N=C -
/ Me3Si-N \ SiMe3
Similar j-elimination of trimethylchlorosilane was also observed in the reaction of &
with lithium bis(trimethylsilyl)amide.
equimolar amounts of LiN(SiMe312
Treatment of &
for 24 hrs. afforded trimethylchloro-
silane, lithium chloride, and trimethylsilylphenylcarbodiimide(65% based on converted 1. :
b. poel 49O; ?~~3_si
2170 Cm-' ,
9.72(9B), ?c6i5 2.95-3.05(5R) in ccl4;
as well as recovered I (6046).
-Ide3SiC1 ) Ph-NCN-SiMe3
Extensive study to utilize the above reactions as synthetic methoa of various chloroformamidines, guanidines, and carbodiimides, is now in progress.
REFERENCES 1. Part IX.
K. Itoh, M. Fukui, Y. Ishii, Tetrahedron Letters, 3867 (1968).
2. bl. F. Lappert, P. B. Prokai, Adv. Orpanometal. Chem., ~01.
3. K. Itoh, S. Sakai, Y. Ishii, J. Org. Chem., 32, 3948(1966). I+. K. Itoh, S. Sakai, Y. Ishii, ibid., 33, 2210 (1967). 5. K. Itoh, Y. Kato, S. Sakai, Y. Ishii, Koayo Kap,akuLasshi, ‘70, 935 (1967) and Chern.Commun.,