2- diisopropylsilyl ethers

Hydroxystyryl)dimethylsilyl Ether (HSDMS-OR) and (2-Hydroxystyryl)diisopropylsilyl Ether (HSDIS-OR)... 

Hetero-Diels-Alder with inverse electron demand Aryl-diisopropylsilyl Diisopropylsilyl ether t-Bu t-Bu OTf-119 a,P-unsaturated carbonyl [241]... 

Curtis and Holmes provided an early display of the synthetic utility of the intramolecular hydrosilylation in their synthesis of the /ran -diol 335, an intermediate in their approach to obtusenyne 336 [130]. The allylic silyl ether 337 was prepared from the corresponding alcohol using an excess of 1,1,3,3-tetramethyldisilazane in the presence of a catalytic amount of ammonium chloride, and then used without purification. A wide variety of catalysts were investigated with the rhodium complex [Rh(acac)(norboma-diene)] providing the best results in terms of stereoselectivity transicis >95 5) (Scheme 10-109). Unfortunately, partial loss of the silyl group under the reaction conditions resulted in a moderate yield of the diol product which was not improved when the corresponding diisopropylsilyl ether was used. 

The DTBS group is probably the most useful of the bifunctional silyl ethers. Dimeihylsilyl and diisopropylsilyl derivatives of diols are very susceptible to hydrolysis even in water and therefore are of limited use, unless other structurally imposed steric effects provide additional stabilization. 

Development of Diisopropylsilyl Solid Supports. A diiso-propylsilyl linker-based sohd support (62) can be synthesized in six steps beginning with silylation of 4-lithioanisole (60) with chlorodiisopropylsilane to form silane (61, eq 19). Substrate loading can be accompUshed by activation of the silane to the silyl triflate followed by addition of the substrate alcohol to form the silyl ether-linked substrate (61). Once the small molecule synthesized on the bead is ready for cleavage, treatment with a 5% solution of HF/pyridine in THF accomplishes efficient recovery of the desired small molecule and in high purity. ... 

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