4- benzyl carbamate to protect amines

Carboxylic acids, protection of, 224-276 as amides and hydrazides, 270-276 as esters, 227-270 Reactivity Chart 6, 433-436 S-Carboxymethyl thioethers, to protect thiophenols, 294-295 Catechols, protection of, 170-174 as cyclic acetals and ketals, 170-172 as cyclic esters, 173-174 Reactivity Chart 4, 425-428 CBZ, see Benzyl carbamates Chloroacetamides, to protect amines, 352-353... 

N-Salicylideneamines, to protect amines, 370 Selective cleavage, 411-412 of benzyl carbamates, 339-340 of benzyl ethers, 49-56 of catechol protective groups, 171 of N- vs. 5-dimethylphosphinothioyl groups, 307... 

The condensation of an aldehyde, benzyl carbamate, and triphenyl phosphite, first described by Oleksyszyn et al., 25,26 affords a direct route to a-aminoalkylphosphonates 4 that are conveniently protected for subsequent reactions (Scheme 4). Since dealkylation of the quaternary phosphonium intermediate 3 is not possible in this case, formation of the pen-tavalent product 4 presumably involves activation of the solvent and formation of phenyl acetate. This method is useful for the synthesis of aliphatic and aromatic amino acid analogues. However, monomers with more elaborate side chains are often incompatible with the reaction conditions. The free amine can be liberated by treatment with HBr/AcOH or by hydrogenolysis after removal of the phenyl esters. The phosphonate moiety can be manipulated by ready exchange of the phenyl esters in alkaline MeOH and activation as described in Section 10.10.2.1.1. Related condensations with other trivalent phosphite derivatives have been reported. 27-30 ... 

Koizumi and co-workers used the optically active allylic chloroselenuranes bearing the 2-exo-hydroxyl-10-bornyl group to obtain optically active allylic amines [41]. The treatment of allylic selenides with f-BuOCl gave the corresponding allylic chloroselenuranes as the only product. Benzyl carbamate, t-butyl carbamate, p-tosylamide, and diphenylphosphinamide were selected as the AT-protected amines for selenimide formation. The nucleophilic reaction of... 

A recent synthesis of both (+)- and (-)-enantiomers of calystegine Aj has been achieved, commencing from the 6-azido derivative of meso-2-cycloheptene-1,4-diol [57]. The amine derived from this compound was protected as the benzyl carbamate (47) and subjected to asymmetrization using Pseudomonas cepacia lipase to give the mono-acetate (48). The product of this reaction was ... 

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