[18135-48-3]  · C6H15ISi  · (3-Iodopropyl)trimethylsilane  · (MW 242.20)

(reagent equivalent to -CH2CH2CH2+1)

Physical Data: clear liquid; bp 84-86 °C/25 mmHg.

Solubility: sol hexane, THF

Preparative Methods: from commerical (3-chloropropyl)trimethylsilane and NaI2 or, alternatively, from the p-toluenesulfonate of commerically available 3-(trimethylsilyl)-1-propanol and NaI.1

Handling, Storage, and Precautions: no detail has been reported. However, the usual handling for common alkyl iodides (e.g. iodohexane) may be followed.

Introduction of 3-(Trimethylsilyl)propyl Group.

Phosphines and amines are alkylated by the title iodide (1) to give silylpropylated compounds (eq 1).3,4

Preparation of 2-Alkylcyclopentanones.

Reagent (1) serves as a -CH2CH2CH2+ equivalent, which is illustrated in a preparation of cyclopentanones from carboxylic acids (eq 2).1,2

Thus alkylation of carboxylic acid dianions with (1) affords the 2-[3-(trimethylsilyl)propyl]alkanoic acids in good yields. After the conversion of these acids to the corresponding acyl chlorides with Oxalyl Chloride, intramolecular acylation of the alkylsilane with Aluminum Chloride affords cyclopentanones in good yields. Examples are shown in eqs 3 and 4.

A related bromide, Me3Si(CH2)3Br, is also known and may be used in a similar way.1

1. Urabe, H.; Kuwajima, I. JOC 1984, 49, 1140.
2. Kuwajima, I.; Urabe, H. OS 1988, 66, 87.
3. Brovko, V. S.; Skvortsov, N. K.; Ivanov, A. Yu.; Reikhsfel'd, V. O. ZOB 1983, 53, 1831 (CA 1984, 100, 6684f).
4. Lesur, B.; Ducep, J. B.; Danzin, C. CA 1992, 116, 59 903p.

Hirokazu Urabe

Tokyo Institute of Technology, Yokohama, Japan

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