Azidotrimethylsilane

Trisubstituted epoxides and trisubstituted epoxysilanes (eqs 3 and 4, respectively) have also been examined. However, these substrates required the addition of ( Pr)2NEt to prevent rearrangement of the epoxide.  

Dealumination of Zeolites. AHFS has been mainly used for the preparation of different materials, mainly inorganic substances. AHFS has been used for the very effective dealumination of zeolites to prepare a number of different materials. These materials include silica nanoboxes and activated zeolite catalysts for the oxidation of benzene to phenol with NO2.  

Christopher G. McDaniel Jon R. Parquette The Ohio State University, Columbus, OH, USA 

Preparative Methods several methods for the synthesis of this azide have been reported. The procedure involving aluminum chloride is not recommended, since an explosive product is formed. Azidotrimethylsilane is now commercially available, and a representative synthetic procedure is as follows. A mixture of sodium azide and chlorotrimethylsilane is refluxed in di-n-butyl ether for 2 days and the azide is safely distilled directly from the reaction vessel. Purer compound (99% content) is obtained by redistillation of the product. Several improved conditions have been reported for the preparation of this azide. In these procedures, trimethylsUyl chloride is reacted with sodium azide either neat or in a high boiling point solvent, such as a mixture of silicone oil and polyethylene glycol. Distillation of the crude product usually provides trimethylsilyl azide (TMSA) in high purity (97.9%) and yield (97%).  

Many applications of TMSA in organic synthesis have been reported but only representative examples are described herein. 

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Recently Keumi et al. (1989) found that arenediazonium tetrafluoroborates readily decompose in the presence of azidotrimethylsilane in DMF solution to afford the corresponding aryl azides. 

In 2007, AntiUa and coworkers described the Brpnsted add-catalyzed desymmetrization of me yo-aziridines giving vicinal diamines [75]. hi recent years, chiral phosphoric acids have been widely recognized as powerful catalysts for the activation of imines. However, prior to this work, electrophiles other than imines or related substrates like enecarbamates or enamides have been omitted. In the presence of VAPOL-derived phosphoric acid catalyst (5)-16 (10 mol%) and azidotrimethylsilane as the nucleophile, aziridines 129 were converted into the corresponding ring-opened prodncts 130 in good yields and enantioselectivities (49-97%, 70-95% ee) (Scheme 53). 

Discoloration of the column Is often observed, which may be due to hydrazoic acid formation upon hydrolysis of the azidotrimethylsilane. 

A. 1-Triisopropylsilyloxy-1-azidocyclohexane A 2-L, two-necked, round-bottomed flask is equipped with a magnetic stirrer, argon inlet, and a rubber septum (Note 1). The flask is charged with freshly-distilled 1-triisopropylsilyloxycyclohexene (25.47 g, 100 mmol. Note 2) and anhydrous dichloromethane (1.0 L, Note 3). Azidotrimethylsilane (68.5 mL, 500 mmol. Note 4) is added via syringe, immediately followed by anhydrous Dowex 50 X 8-100 (24.98 g. Note 5) in a single portion from a dry flask. The suspension is stirred vigorously at ambient temperature for ca. 48 hr (Note 6). The reaction mixture is filtered to recover the Dowex resin and solvent is removed under reduced pressure to... 

The azidotrimethylsilane was purchased from Acros Organics and used without further purification. 

With azidotrimethylsilane in the presence of a stoichiometric amount of a chiral complex prepared from dichlorodiisopropoxy titanium(IV) and di-rm-butyl L-tartrate, (15,2.S )-1,2-azido alcohols are obtained only in moderate yield with moderate enantiomeric excess1040. 

The known adduct (385) of furan and vinylene carbonate, previously used for the synthesis of some cyclitols,256,257 has been transformed into DL-ribose derivatives. After hydroxylation of 385 and subsequent formation of the isopropylidene derivative, the carbonate group was removed by treatment with barium hydroxide, and the resulting diol was cleaved by oxidation with permanganate. Dicarboxyl-ic acid 386 gave, upon treatment with acetic anhydride, cyclic anhydride 387. The reaction of 387 with azidotrimethylsilane produced... 

The following procedure is an operatively simple route for the synthesis of bromotrimethylsilane on a preparative laboratory scale from reagents that are readily accessible and inexpensive. This could be a method of choice in some laboratories despite the fact that bromotrimethylsilane is now commercially available (Petrach Systems, Aldrich, or Alpha). Moreover, the procedure also serves as a suitable method for the synthesis of azidotrimethylsilane and isocyanatotrimethylsilane, and is specially useful for the preparation of cyanotrimethylsilane. Thus a mixture of triphenylphosphine dibromide, hexamethyldisiloxane, and a catalytic amount of powdered metal zinc in 1,2-dichlorobenzene is heated under reflux to produce bromotrimethylsilane in nearly quantitative yield, which is simultaneously distilled over a suspension of the corresponding pseudohalogenoacid salt in N, /V-dimethylformamide as solvent.6... 

Isocyanates (5, 719).1 The reaction of acid chlorides with azidotrimethylsilane is catalyzed by trace amounts of powdered KN3 and 18-crown-6. For instance the ncid chloride I only undergoes reaction with the silane under catalysis. 

Review Synthetic applications of cyanotrimethylsilane, iodotrimethylsilane, azidotrimethylsilane, and mcthylthiotrimcthylsilanc have been reviewed (108 references). 

Imino thioethers,2 The reagent, prepared in situ, converts the dimethyl thioketal of a cyclic ketone (2) into the imino thioether 3 in high yield. The reaction can also he carried out with azidotrimethylsilane (1 equivalent), stannic chloride (1 equivalent), and iodine (10 mole %). but yields arc lower. This reaction was examined because of the reaction of thiokctals with iodine azide (this volume). 

N3)2Ti(0-i-Pr)2 (l) 10 azidohydrins. Azidotrimethylsilane reacts very slowly in the presence of Ti(0-/-Pr)4 with epoxides to form azidohydrins. The reaction is more rapid when catalyzed by 1. Actually 1 is a superior reagent for cleavage of 2,3-epoxy alcohols.11 Examples ... 

Arenediazonium tetrafluoroborates, 19 Azidotrimethylsilane, 24 N-Chlorosuccinimide, 79 Diphenyldiazomethane, 242 a-Substituted a-amino acids a-Methylbenzylamine, 185 Methyl N-benzyloxy carbonyl-a-chloro-glycinate, 186 Pivaldehyde, 249 Miscellaneous compounds Diisobutylaluminum hydride-Boron trifluoride etherate, 116 Tin(IV) chloride, 300 Amino alcohols... 

Amino alcohols Azidotrimethylsilane, 24 Benzyl isocyanate, 30 Diethylamine, 312 Morpholine, 14 Pyrrolidine, 14... 

Azidotrimethylsilane, 24, 217 Diazidodiisopropoxytitanium, 217 Sodium azide-Methyltrioctylammonium chloride, 240 Aziridines... 

Azidotrifluoromethane, see Trifluoromethyl azide, 0346 f Azidotrimethylsilane, see Trimethylsilyl azide, 1310... 

In 1991, Duncia et al. reported on the synthesis of 1,5-disubstituted tetrazoles from secondary amides and azidotrimethylsilane under the conditions of the Mitsunobu reaction <1996CHEC-II(4)621>. The Mitsunobu protocol was successfully applied to the conversion of AT(cyanoethyl)amide into tetrazole 510. The tetrazole ring in this event forms by the cyclization of an imidoyl azide (not shown in the scheme) whose precursor is the phosphonium imidate 509 (Scheme 67) <2000JME488>. 

Azido alcohols.1 This azide is considerably more reactive for cleavage of epoxides than azidotrimethylsilane, which requires a Lewis acid promotor. Although DMF enhances the reactivity of the silyl azide, it lowers the reactivity of the stannyl azide. The reactivity of the latter azide is also decreased by neighboring ester, acetonide, or ether groups. 

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