Trichloromethyl carbonate

Triphosgene (bis(trichloromethyl)carbonate) has been used to deoxochlorinate [VOCh] - to [VClfi] - and [V02Cl2] to [VOCh] [6]. In both these cases the deox-ochlorination was accompanied by spontaneous reduction of the initial products (Scheme 6.1-2). 

R1 = aryl, alkyl, benzyl, PhCH2OCH2, (EtO)2CHCH2, (EtO)2CHCH2CH2 or 2-aminoethyl R2 = aryl, alkyl, cyclohexen-1-yl or (EtO)2CH E+ = l2, C02, CIC02Me, HC02Et, PhCHO, PhNCO, trichloromethyl carbonate, or carbamoyl chloride... 

Bis(2-diisopropylaminoethyl) Disulfide Bis(2-diisopropylaminoethyl) Sulfide Bis(2-fluoroethyl) 2-Chloroethylamine Bis(2-fluoroethyl)methylamine Bis(2-hydroxyethyl) Sulfide Bis(2-hydroxyethyl) Thioether Bis(2-hydroxyethyl)amine Bis(2-hydroxyethyl)methylamine Bis(2-propenyl) Sulfide Bis(bromomethyl) Ether Bis(chloromethyl) Ether Bis(cyclohexyl)carbodiimide Bis(ethenyl)sulfone Bis(trichloromethyl) Carbonate Bis(/3-bromoethyl) Sulfide Bis(/3-chloroethyl)ethylamine Bis(/3-Chloroethyl)methylamine Bis(/3-chloroethylthio)ethane Bis(/3-mercaptoethyl) Sulfide... 

Regioselective protection of the pentaol 230 with bis-trichloromethyl carbonate and subsequent acetic anhydride treatment affords the C-10 acetoxy C-l, C-2 carbonate compound 231 in good yield. Deprotection of the acetonide function and regioselective silylation of the C-7 hydroxyl group, followed by... 

Synthesis of the tricyclic [l,2,4]triazolo[l,5-c][l,3]benzoxazine 290 was described by an Italian group <1994FA89, 1995JME2196>. These authors reacted the triazolylphenole 289 with bis-trichloromethyl carbonate to obtain the tricyclic product 290 in poor to good yield. 

WH Daly, D Poche. The preparation of V-carboxyanhydridcs of a-amino acids using bis(trichloromethyl)carbonate. Tetrahedron Lett 29, 5894, 1988. 

More recent developments favor bis(trichloromethyl)-carbonate, which is produced by exhaustive photochlorination of dimethyl carbonate. 

Scheme 36 SPPS of N-Alkylated Peptides by the Bis(trichloromethyl) Carbonate Method,3°l...

A slightly modified version of the bis(trichloromethyl) carbonate method 30 has been used for the total SPPS of cyclosporin O 29 (Scheme 1) and omphalotin A 40 (Scheme 37). Since in this case an acid sensitive trityl resin was used, excess DIPEA was added to the resin. 

Bis(trichloromethyl) Carbonate Mediated Coupling General Procedure 1301... 

Fmoc-peptide-resin was deprotected with 20% piperidine/DMF (2 min+8 min). After washing, the resin was treated with dry THF (1 mL) for 15 min. Meanwhile, the Fmoc amino acid (3.5 equiv) was added to a 68 mM soln of bis(trichloromethyl) carbonate in dry THF [1.15 mM of bis(trichloromethyl) carbonate]. 2,4,6-Collidine (10 equiv) was added to the clear soln, upon which a precipitate of collidinium chloride formed. DIPEA (8 equiv) was added to the resin, immediately followed by addition of the suspension. The mixture was shaken for the times given in Scheme 39, filtered, and washed. 

Triphenylpyrilium perchlorate, 3833 Triphenylsilyl perchlorate, 3744 Triphenyltin hydroperoxide, 3752 Triphosgene, see Trichloromethyl carbonate, 1039b Triphosphorus pentanitride, 4770 Tripotassium hexafluoroferrate(3-), 4353 Tripropylaluminium, 3209 Tripropylantimony, 3215... 

Sodium sulfide Glass, 4805 Trichloromethyl carbonate, 1039 See also INSULATION, PAPER TOWELS... 

L. Cotarca, P. Delogu, A. Nardelli, V Sunjic, Bis(trichloromethyl) Carbonate in Organic Synthesis, Synthesis 1996, 553-576. 

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