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Reactions >> Protecting Groups >> Stability

Benzylamines

Bn-NR2

T. W. Green, P. G. M. Wuts, Protective Groups in Organic Synthesis,
Wiley-Interscience, New York, 1999, 579-580, 744-747.

 

Stability

H2O: pH < 1, 100C pH = 1, RT pH = 4, RT pH = 9, RT pH = 12, RT pH > 12, 100C
Bases: LDA NEt3, Py t-BuOK Others: DCC SOCl2
Nucleophiles: RLi RMgX RCuLi Enolates NH3, RNH2 NaOCH3
Electrophiles: RCOCl RCHO CH3I Others: :CCl2 Bu3SnH
Reduction: H2 / Ni H2 / Rh Zn / HCl Na / NH3 LiAlH4 NaBH4
Oxidation: KMnO4 OsO4 CrO3 / Py RCOOOH I2, Br2, Cl2 MnO2 / CH2Cl2

Protection


A highly active Mn(I) pincer catalyst enables an atom-economic and highly efficient N-alkylation of amines with alcohols utilizing the borrowing hydrogen methodology. A broad range of anilines and more challenging aliphatic amines were alkylated with primary and secondary alcohols. The reaction offers low catalyst loadings and mild reaction conditions.
L. Homberg, A. Roller, K. C. Hultzsch, Org. Lett., 2019, 21, 3142-3147.


Other Syntheses of Benzyl-Protected Amino Groups


A highly efficient general strategy for the synthesis of 2-amino acids by homologation of α-amino acids, involving the Reformatsky reaction with a Mannich-type imminium electrophile is reported.
R. Moumne, S. Lavielle, P. Karoyan, J. Org. Chem., 2006, 71, 3332-3334.


Deprotection


A chiral thiourea catalyzes the highly enantioselective hydrophosphonylation of a wide range of N-benzyl imines. Subsequent deprotection by hydrogenolysis provides access to free α-amino phosphonic acids in highly enantioenriched form.
G. D. Joly, E. N. Jacobson, J. Am. Chem. Soc., 2004, 126, 4102-4103.


Formation of a bromo radical through the oxidation of bromide under mild conditions enables an oxidative debenzylation of N-benzyl amides and O-benzyl ethers to provide the corresponding amides and carbonyl compounds in high yields.
K. Moriyama, Y. Nakamura, H. Togo, Org. Lett., 2014, 16, 3812-3815.


Conversion of Benzyl-protected Amines to other functional groups


A highly efficient general strategy for the synthesis of 2-amino acids by homologation of α-amino acids, involving the Reformatsky reaction with a Mannich-type imminium electrophile is reported.
R. Moumne, S. Lavielle, P. Karoyan, J. Org. Chem., 2006, 71, 3332-3334.