ISSN:
0009-2940
Keywords:
Lithiation
;
Aminomethylation
;
Nitrogen heterocycles
;
Diazasilaheterocycles
;
Diazaphosphaheterocycles
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The aminals tetramethylmethylenediamine (TMMDA) la, dicyclohexyldimethylmethylenediamine (CMMDA) lb, and di-isopropyldimethylmethylenediamine (IMMDA) lc are doubly metalated by LitBu to give LiCH2N(R)CH2N(R)CH2Li [2a: R = Me, 2b: R = Cy (Cy = cyclohexyl), 2c: R = iPr], which precipitate out of pentane as highly pyrophoric substances. Deuteration confirms N-methyl metalation exclusively. A series of aminomethylation reactions were performed by means of the doubly lithiated aminals 2a-c. The reactions of 2a-c with monochlorosilanes yield the silylated species R′3SiCH2MN(R)CH2N(R)CH2SiR′3 (3a: R′= Me, R == Me; 3b: R′ == Me, R == Cy; 3c: R′= Me, R = iPr 4: R′= Ph, R = Me, see Scheme 2). The use of dichlorosilanes lead to six-membered heterocycles 6a-6d. 6a is transferred into a mono quarternary ammonium salt 7 by methylation with MeI. The spirocycle 8 is obtained from SiCl4 and two equivalents of 2a. Similarly, several substituted 1,3-diaza-5-phosphacyclohexanes 9a-e (R1 = Me, Ph, NPh2, NCy2, see Scheme 3) are synthesized by the reaction of dichlorophosphanes R1PC2, with 2a and 2b, respectively. Oxidation of 9d with sulfur yields 12a, which is characterized by X-ray structure determination.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19971301212
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