Amines trichloroethoxycarbonyl

Troc = 2,2,2-trichloroethoxycarbonyl Figure 9.72. Enantioselective amination of enolsilanes. 

Synthesis of l,2-frans-2-Acetamido-2-deoxyglycosyl Amino Acids Using Carbamate (2,2,2-Trichloroethoxycarbonyl or Allyloxycarbonyl) Protection of the Amine... 

The reactions described so far all yield medium-ring tertiary amines. Reinecke s group have recently extended their methods to synthesize the more useful secondary amines.288 Three syntheses were developed. The first [Eq. (31)] involves reductive cleavage of the benzyl indolizidinium salt 229 with lithium aluminum hydride, followed by replacement of the benzyl group with the labile trichloroethoxycarbonyl group. The latter may be removed under mild conditions with zinc-methanol, which does not cause migration of the double bond. 

SCHEME 14.1 Synthesis of lipids I and II by VanNieuwenhze et al. Bn, benzyl CDI, l,l -carbonyldiimidazole DBU, l,8-diazabicyclo[5.4.0]undec-7-ene DIPEA, diisopropylethyl-amine EDC, l-ethyl-3-(3-dimethylaminopropyl)carbodiimide NHS, A-hydroxysuccinimide Pyr, pyridine TFA, trifluoroacetyl Troc, 2,2,2-trichloroethoxycarbonyl. 

Cleavage of fl-halourethanes. Eckert and Ugi have found that urethanes of this type can be cleaved to the amine by treatment with the anion of 1 in acetone or methanol at room temperature. The reaction involves alkylation followed by reductive fragmentation (equation I). The rate of cleavage depends on the structure of the blocking group 2,2,2-trichloroethoxycarbonyl derivatives (R = R = C1) are cleaved within 1-5 minutes. Cobalt(II) phthalocyanine (1) is recovered in almost quantitative yield in reusable form. 

H-1,2,3-Triazoles, l-alkyl-4,5-dihydro-, 153 1/f-1,2,4-Triazoles, l-farylsulfonyl)- nucleotide condensation with, 218 2H-1,2,3-Triazoles, 2-alkyl- synth., 151-152 2 2-Tribromoethoxycarbonyl (Tbeoc) protected alcohols and amines, 157-158, 163 2,2,2-Trichloroethoxycarbonyl (Tceoc) protected alcohols and amines, 157-158,162-163 2,2 -Trichloroethyl (Tee) protected phosphates, 166-167, 216, 218... 

Recently, Iwao reported (57) the dehydrative cyclization of 119 in the total synthesis of /-clavicipitic acid. Iwao prepared the diester 118, having protected the amino group with a trichloroethoxycarbonyl group, which was then readily cleaved by treatment with zinc dust to recover the free amine 119 in... 

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