N-Pivaloyl-2-

To see whether water could be activated and added to Jt-systems other than alkynes, the metal-catalyzed hydrolysis of nitriles was studied [20]. For this purpose novel homodimeric and heterodimeric bis(acetylacetonato)ruthenium(ii) complexes bearing the 6-diphenylphosphino-N-pivaloyl-2-aminopyridine (10a) and 3-diphenylphosphinoisoquinolone (Ila) ligands were prepared. The molecular structures of these precatalyst were studied in solution and also in the solid state and revealed some unusual hydrogen-bonding patterns, in particular for the heterodimeric system in which the acetylacetonato ligand is involved (Scheme 2.7). 

Methoxy-1,2,3,4-tetrahydroisoquinoline has been obtained through lithiation with butyllithium between the methoxyl group and the side-chain in N-pivaloyl 2-(3-methoxyphenyl)ethylamine (X = H), formylation with dimethylformamide to give the formyl compound (X = CHO), followed by cyclisation with 10% hydrochloric acid and finally reduction with sodium borohydride (ref. 150). 

That the combined DMG effects of OMe and N-pivaloyl are not necessary was demonstrated by the metalation of the simple 2-, 3-, and 4-N-pivaloyl pyridines 203 to give, after electrophile quench, products 204 (Scheme 61) (82S499 83JOC3401 89JHC105). Using n-BuLi (2.5 equiv./ TMEDA/Et20/ - 10°C) or n-BuLi (2.5 equiv./THF/0°C) conditions, a variety of substituted amino pyridines 205-207 were thereby prepared. In all cases, regiospecific metalation at the most acidic site was observed. For example, metalation of the 3-N-pivaloyl isomer 203 at -40°C occurred at... 

A convenient four-step synthesis of 2-amino-3-pyridinyl, 3-amino-4-pyridinyl, and 4-amino-3-pyridinyl phenylmethanones 250 begins with the three isomeric N-pivaloyl pyridines 247 and involves the intermediate carbinols 248 (Scheme 75) (89JHC105). 

Metalation of either 4-N-pivaloyl or 4-N-f-Boc aminopyridines 269 followed by the bis electrophile, 3-chloro-l-iodopropane, furnishes the tet-rahydro-l,6-naphthyridine 270 (Scheme 80) (88TL5725). Application of this reaction to the corresponding 2-aminopyridines gives access to the corresponding 1,8-naphthyridine. 

Rather sparse utility of N-pivaloyl and N-f-Boc DMGs has been documented to date. A more direct preparation of 1,2-related aminoketo pyri-dines, of value as intermediates for pyrido-l,4-diazepine synthesis, to... 

C12H15N04 N-carbobenzyloxy-2-methyl alanine 15030-72-5 25.00 1.1892 2 24307 C12H17NO N-pivaloyl-o-toluidine 61495-04-3 23 1 050 ... 

C12H17NO N-pivaloyl-o-toluidine 61495-04-3 551.15 48.820 2 24456 C12H180 6-phenyl-1-hexanol 2430-16-2 524.28 46.221 2... 

Butyllithium was purchased from Aldrich Chemical Company, Inc., and titrated with N-pivaloyl-o-toluidine.2 The checkers observed that use of less concentrated solutions of BuLi resulted in longer reaction times. 

Metges,C.C.,Daenzer,M.(2000) 13Cgaschromatography-combustion isotope ratio mass spectrometry analysis of N-pivaloyl amino acid esters of tissue and plasma samples. Analytical Biochemistry, 278(2), 156-164. 

C27H33FgN202Rh, 1-((Di(pivaloyl)methanato)bis(pyridine)rhoda)-2,3-bis(trifluoromethyl)cyclopent-2-ene, 46B, 814 C2 7H3 uClzNPPt, Dichloro(1 -(N,N-diethylammoniomethyl)-2 methylprop-1-enyl)(triphenylphosphine)platinum(II), 44B, 715 C27H3sFe207Si4, Bis[1,4-bis(trimethylsilyl)buta-1,3-diyne]heptacar-bonyldiiron, 45B, 881... 

Figure 1. Mass fragment pattern of the N-pivaloyl-(S)-2-butyl esters of the D- and L-alanine diastereoisomers.

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