Triisopropylsilyl

Pyrroles and indoles can be protected with the r-butyldimethylsilyl group by treatment with TBDMSCl and n-BuLi or NaH. Triisopropylsilyl chloride (NaH, DMF, 0°-rt, 73% yield) has been used to protect the pyrrole nitrogen in order to direct electrophilic attack to the 3-position.It has also been used to protect an indole.This derivative can be prepared from the silyl chloride and The silyl protective group is cleaved with Bu4N F , THF, rt or with CF3COOH. 

Trimethylsilyl, 429 Triethylsilyl, 429 f-ButyIdimethylsilyl, 430 FPropyIdimethylsilyl, 430 Phenyidimethylsilyl, 431 Di-f-butylmethylsilyl, 431 Triisopropylsilyl, 431... 

Silyl-derived protective groups are also used to mask the thiol function. A complete compilation is not given here, since silyl derivatives are described in the section on alcohol protection. The formation and cleavage of silyl thioethers proceed analogously to those of simple alcohols. The Si-S bond is weaker than the Si-O bond, and therefore, sulfur derivatives are more susceptible to hydrolysis. For the most part, silyl ethers are rarely used to protect the thiol function, because of their instability. Silyl ethers have been used for in situ protection of the-SH group during amide formation. The use of the sterically demanding and thus more stable triisopropylsilyl thioether may prove worthwhile. ... 

The cleavage of this group is reported to be similar to that of the triisopropylsilyl analogue. 

Triisopropylsilyl group of 2-[l-triisopropylsilyl-l//-indol-6-yl)perhydro-pyrido[l,2-u]pyrazine was removed by treatment with BU4NF in THF (01MIP5). 

It was anticipated all along that the vinylsilane residue could serve as a vinyl iodide surrogate. After protection of the C-14 secondary hydroxyl in 180 in the form of a triisopropylsilyl ether, the vinyltrimethylsilyl function can indeed be converted to the requisite vinyl iodide with AModosuccinimide (NIS) (see 180—>181, Scheme 43). Vinyl iodide 181 is produced stereospecifically with retention of the A17,18 double bond geometry. This transformation is stereospecific since the stereochemistry of the starting vinylsilane and the vinyl iodide product bear a definite relationship to each other.67b 75... 

The completion of the synthesis of 1 only requires two deprotection steps. Hydrogenolysis of the four benzyl ethers, followed by cleavage of the triisopropylsilyl ether with hydrofluoric acid in acetonitrile, provides paeoniflorin (1) in an overall yield of 92 %. 

GjHjiOjP 116-17-6) see Clodronate disodium (3/t,45)-3-(triisopropylsilyloxy)-4-phenyl-2-azetidinone (C nH2()N02Si 132127-31-2) see Docetaxel triisopropylsilyl trifluoromethanesulfonate (C ()H2 F303SSi 80522-42-5) see Tacrolimus... 

On the way to cydo-Cig, l,6-bis(triisopropylsilyl)-l,3,5-hexatriyne (2) [50] was subjected to reaction with [Co2(CO)8], followed by ligand exchange with the bridging bis(diphenyphosphino)methane (dppm) ligand, whereupon smooth deprotection yielded the stable dark-red dicobalt complex 3 (Scheme 1). Oxida-... 

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