T-Butyl isocyanate

Butane-1,4-diisocyanate, 2376 t Butyl isocyanate, 1931 4-Chlorophenyl isocyanate, 2648 1,6-Diisocyanatohexane, 3008 Diisocyanatomethane, 1079 2,4-Diisocyanatotoluene, 3117 t Methyl isocyanate, 0761... 

When a toluene solution of a mixture of cyclotrisilane 34 and cyclohexyl isocyanate (or f-butyl isocyante) was heated at 70 °C, cyclic di- and trisiloxanes 37 and 38, i.e. the cyclic dimer and trimer of the silanone 36, were obtained together with the corresponding isonitrile RN=C. The formation of 37 as well as 38 was completely suppressed in the presence of hexamethylcyclotrisiloxane (19 D3) instead, quantitative conversion of 35 into 39, the formal insertion product of the silanone 36 into the Si—O bond of D3, occurred (Scheme 14). Since neither cyclodisiloxane 37 nor cyclotrisiloxane 38 reacted with D3 under the reaction conditions, the possibility that 37 or 38 is the precursor of 39 was ruled out. Whereas the oxidation of 35 with cyclohexyl and t-butyl isocyanates proceeded with exclusive formation of 37 and 38 (as the silicon-containing compounds) the reaction of 35 with phenyl isocyanate resulted in the formation of 37 in low yield. Furthermore, in this case the presence of D3 did not totally suppress the formation of 37. According to the authors, these results indicate that the oxidation of 35 with cyclohexyl and f-butyl isocyanates appears to use other reaction channels than that with phenyl isocyanate. 

In 1976, Saegusa reported the copper(I) t-butoxide-promoted deoxygenation of C02 by t-butyl isocyanide to produce t-butyl isocyanate and CO (Equation 6.13) [111a]. 

R,3S)-p-Phenyl-isoserine methyl ester (4.35 g, 22 mM) is dissolved in dry THF (100 ml) and the flask cooled to 0°C. To the mixture is added t-butyl isocyanate (2.8 ml, 25 mM). TLC after 15 min shows some starting material left so additional isocyanate (0.5 ml) is added. TLC after 1 h shows no starting material so the solvent is concentrated under reduced pressure to give the N-(t-butylaminocarbonyl)-p-phenyl isoserine methyl ester. 

An exchange reaction of a tellurium diimide dimer with t-butyl isocyanate affords di-t-butylcarbodiimide and N,N -bis(t-butyl)ureato dimer. ... 

Also, reaction of t-butyl isocyanate with LiN(SiMc3)2 14 affords N-t-butyl-N -trimethylsilyl-carbodiimide 15 in 56% yield. ... 

The reactivity of zirconium imido complexes supported by a dibenzotetraaza[14]annulene (taa) macrocycle ligand toward a range of unsaturated substrates has been examined. Reaction with t-butyl isocyanate cleanly generated the cycloaddition product Zr N(2,6-( -Pr)2C6H3)C(0)N(t-Bu) (Me4taa) (equation 21). ... 

When ultrasonihcation (US) is applied to the reaction of a bromobenzene with t-butyl isocyanate and butyl lithium in diethyl ether or THF, a considerable improvement in time and yield is obtained addition of DMF at a low temperature induces cyclization [3184a). The use of ultrasonihcation in organic chemistry has been reviewed [B-58, 3615, 3646]. 

NN -Di-t-butylsulphurdi-imide (10) and iV-t-butyl-N -phenylsulphurdi-imide react with halogeno- and organo-sulphonyl isocyanates (11) to form IV-organyl-iV -sulphonylsulphurdi-imides (12) and t-butyl isocyanate [equation (10)]. At... 

Several new methods for the preparation of ketenimines have appeared. Perfluoro-t-butyl isocyanate behaves nonnally in a Wittig reaction with the ylide (174), leading to the diphenylketenimine (175), but the method may not be generally applicable because periluoro-n-propyl isocyanate yields instead an azabutadiene, which presumably arises by isomerization of the first-formed ketenimine (see Scheme 6). Analogous rearrangements of fluoroketens are well documented. ... 

Butyl isocyanate. See Isobutyl isocyanate t-Butyl isocyanate n-Butyl isocyanate n-Butyl isocyanate... 

Manuf./Distrib. ABCR http //www.abcr.de Aldrich http //www.sigma-aidrich.com Alfa Aesar http //www.aifa.com Bayer http //www.bayerus.com Lancaster Synthesis TCI Am. http //www.tciamerica.com Xi nchem http //WWW. finechemnet. com t-Butyl isocyanate... 

Isocyanic acid, t-butyl ester. See t-Butyl isocyanate... 

Propane, 1,2-epoxy, 3,3,3-trichloro-. See 1,2-Epoxy-3,3,3-trichloropropane Propane, 1,1 -(ethylidenebis (oxy)) bis-. See Acetaldehyde dipropyl acetal Propane, 2-isocyanato-2-methyl-. See t-Butyl isocyanate... 

Allyl isocyanate n-Butyl isocyanate t-Butyl isocyanate 3-Chloro-4-methyl phenyl isocyanate 2-Chlorophenyl isocyanate Cyclohexyl isocyanate 2,3-Dichlorophenyl isocyanate 2,4-Dichlorophenyl isocyanate 2,5-bichlorophenyl isocyanate 2,6-Dichlorophenyl isocyanate 3,4-Dichlorophenyl isocyanate Ethyl isocyanate Hexyl isocyanate Isobutyl isocyanate Isopropyl isocyanate Methacrylonitrile Methoxymethyl isocyanate n-Propyl isocyanate m-Tolyl isocyanate o-Tolyl isocyanate p-Tolyl isocyanate intermediate, aminimides 1,1-Dimethylhydrazine intermediate, ampicillin Acetamide... 

Aiiyi isocyanate n-Butyl isocyanate t-Butyl isocyanate 3-Chloro-4-methylphenyl isocyanate 2-Chlorophenyl isocyanate Cyclohexyl isocyanate 2,3-Dichlorophenyl isocyanate 2,4-Dichlorophenyl isocyanate 2,5-Dichlorophenyi isocyanate 2,6-Dichiorophenyi isocyanate... 

Diethyl pyrocarbonate 1609-86-5 t-Butyl isocyanate 1623-19-4 Triallyl phosphate 1629-58-9 Ethyl vinyl ketone... 

Diethyl pyrocarbonate 216-544-9 t-Butyl isocyanate 216-624-3 Ethyl vinyl ketone 216-633-2... 

The structures of the adducts derived from [2 + 2]cycloaddition of methyl-t-butylcarbodi-imide and various other heterocumulenes are conveniently assigned by a study of their fragmentation products. In one case the method was used to correct a previously assigned structure the adduct from benzoyl isocyanate and the carbodi-imide has the structure (227) rather than the previously proposed (228) since on thermolysis it gives t-butyl isocyanate... 

Protection and Deprotection.—N-Protected a-amino-acids are readily esterified by methanol or ethanol in 60—80% yield after reaction with an enamine (e.g. from isobutyraldehyde and piperidine) and t-butyl isocyanate. Such amino-acids can also be esterified efficiently with alkyl halides under phase-transfer conditions with no racemization. Direct esterification of a-amino-acids with ethyl toluene-p-sulphonate in boiling ethanol gives a-amino-acid ethyl esters in 80—90% yield as the sulphonate salts. The protection of acid functions by formation of the 2-chloro-(or bromo-)ethyl esters has been discussed. These derivatives survive exposure to both moderately acidic and basic conditions and are removable by conversion into the iodoethyl analogues followed by zinc reduction. Alternatively, they may be converted into hydrophilic ammonium or phosphonium salts which exhibit enhanced acid stability but which are cleaved by very dilute base. Yet another method for the removal of such groups using supernucleophilic Co phthalocyanin anions has been reviewed. Further routes to 2,2,2-trichloroethyl esters have been described, one of which employs an activated ester intermediate and is suited to acid-labile substrates. 

Often the initially formed bonds at low temperature are not the ones that are isolated at room temperature. Also the electronic configurations play a part in product formation. For example, in the [2+2] cycloaddition reaction involving two carbodiimides the more nucleophilic carbodiimide attacks the more electrophilic carbodiimide giving rise to the formation of only one reaction product. The latter reactions proceed stepwise, while sometimes concerted reactions are observed. Sterical hindrance also plays an important role in product formation. We have utilized A-methyl-A -t-butylcarbodiimide as a probe in determining the structure of the derived cycloadducts, because the reaction always proceeds via addition across the C=N bond with the methyl substituent. For example, in the [2+2] cycloaddition reaction with benzoyl isocyanate the reaction proceeds across the C=0 bond of the isocyanate, because t-butyl isocyanate is the only product generated in the retro reaction... 

In the reaction of t-BuN=Te=N-t-Bu with t-butyl isocyanate, the [2+2] cycloadduct was obtained... 

In the reaction of the formaldehyde zirconium dimer 323 with t-butyl isocyanate the double insertion product 324 is isolated. ... 

Alkyl isocyanates insert into tungsten and iron hydride complexes to give the insertion products resulting from insertion into the metal-hydrogen bond. For example, reaction of CpW(CO)3H with methyl isocyanate affords the carbamate complex . Likewise, CpFe(CO)2H reacts with t-butyl isocyanate to give the carbamate complex 329 . 

Evidence for the proposed structures of the four-membered ring [2+2] cycloadducts is provided by the retroreaction of the Al-methyl-A-t-butylcarbodiimide adduct 63, which affords t-butyl isocyanate rather than methyl isocyanate expected for the isomeric structure . 

Singlet oxygen also adds across the C=C bond in C,A-di-t-butylketenimine at -78 °C to give 65, but the cycloadducts undergo cycloreversion to give a mixture of the corresponding aldehyde and t-butyl isocyanate... 

In a similar manner the dioxetanimine 67 is obtained in the reaction of the ketenimine 66 with singlet oxygen at —45 °C, but the cycloadduct is unstable and dissociates into A-methylacridine and t-butyl isocyanate... 

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