Triisopropylsilyl groups

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). 

Fig. 20 (a) Fluoride sensing with coumarin leuko dye 52 and (b) time-dependent spectroscopic response of the reaction TIPS = triisopropylsilyl group. (Reprinted in part with permission from [143], Copyright 2003 Wiley-VCH)... 

The enlargement of the bond angle caused by the triisopropylsilyl groups was encouraging with regard to the prospects of [(i-Pr)3Si]2Si having a triplet ground state. It was found, however, that the addition of [(i-Pr)3Si]2Si is totally stereospecific as seen for the reaction with cA-2-butene (Eq. 1). One explanation is that the... 

Sterically controlled regioselective para-substitution of aniline has been achieved by introduction of sterically demanding l-isopropyl-2-methylpropyl or triisopropylsilyl groups at the nitrogen of aniline using a lithiation-substitution sequence.71... 

The triisopropylsilyl group gave comparable satisfactory results.7... 

As in the above system, the triisopropylsilyl group has proved to be a convenient stopper for the ends of polyether chains incorporating hydroquinone derivatives even though other bulky groups, such as adamantoyl, have also been used. Indeed, by fine-tuning the size of the stoppers, in specific instances the cyclic com-... 

On the other hand, the 0-triisopropylsilyl group of 100b cannot direct the cyclopropana-tion reaction and causes non-bonding interaction to restrict rotation about the Cl to C2 bond and covers the front face of the amide moiety. Thus, the (iodomethyl)zinc reagent approaches from the backside of the amide group, resulting in higher diastereoselectivity. ... 

Very electron-rich aromatic systems interact with acid chlorides and anhydrides in the absence of a catalyst to afford good yields of ketones. Reactions of pyrrole and substituted pyrroles exemplify these reactions. The oxalylation shown in equation (18) was part of the synthesis of a complex, highly functionalized antitumor agent. Use of the triisopropylsilyl group to direct reaction to the 3-position (equation 19) is noteworthy. ... 

The Triisopropylsilyl Group in Organic Chemistry Just a Protective Group, or More Rucker. C. Chem. Rev. 1995, 95, 1009. 

There are exceptions to the rule. For instance, when there is a bulky group on the nitrogen such as triisopropylsilyl group (TIPS), bromination occurs predominantly on the C3 (P) position instead of on the C2 (a) position. ... 

The most commonly used protecting group for acetylenes is the trimethylsilyl (TMS) group.f Thus, commercially available trimethylsilylacetylene provides an excellent starting material for the synthesis of aryl and alkenyl acetylenes. Triisopropylsilyl groups are also useful for the step wise deprotection with TMS groups (Scheme 37). Cross-coupling of aryl or alkenyl halides with trimethylsilylacetylene proceeds in the presence of a Pd catalyst and Cul, followed by treatment with dilute aqueous or in... 

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