Aldehydes Ammonium carbamate

Fulop and co-workers [124] have reported the synthesis of some new (ami-noalkyl) naphthols and (aminoalkyl) quinolinols 85 in good yields through a one-pot, microwave-assisted three-component modified Mannich reaction of naphthol or quinolinol with two equivalents of an aldehyde using ammonium carbamate or ammonium hydrogen carbonate as solid ammonia sources. It was observed that aliphatic aldehydes did not lead to the formation of the desired (aminoalkyl) quinolinols 85 (Scheme 64). 

An improved method for the preparation of nitriles and thiocyanates from halides with benzyltrimethylammonium salts and a convenient preparation of both aliphatic and aromatic nitriles from aldehydes through N,N,N-trimethylhydrazonium salts have been reported. Nitriles can be easily converted into amidines with ammonium halides . Acylisocyanates can be conveniently prepared from amides with oxalyl chloride . A simple preparation of alkyl and aryl carbamates with N-carbonylsulfamic acid... 

In the synthesis of (lS,8aS)-(- -)-indolizidin-l-ol (88) by Chandrasekhar and coworkeis, the aldehyde 104 derived from D-glucose was converted in situ into the N-benzyHmine, to which was added but-3-enylmagnesium bromide to give the adduct (—)-105 as the sole diastereomer in 72% yield after chromatographic purification (Scheme 10). Protection of the amine as the Cbz carbamate and hydroboration—oxidation of the terminal alkene afforded alcohol (—)-106 which, after debenzylation with ammonium formate and palladium on carbon, needed to be re-protected with Cbz. 

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