Categories: C-C Bond Formation > Nitrogen-containing molecules >
Synthesis of β-Amino Acids and Derivatives
Recent Literature

Mannich-rype reactions of secondary amines, aldehydes and ketene silyl acetals
were efficiently promoted by catalytic amounts of diarylborinic acid esters,
affording β-amino esters selectively with no formation of the corresponding
β-hydroxy esters.
Y. Tanaka, T. Hasui, M. Suginome, Synlett, 2008, 1239-1241.

Aminoboranes are highly efficient and mild iminium ion generators in the
Mannich-type aminative coupling of aldehydes with silyl ketene acetals. The
use of diisopropylaminoboranes enables a three-component Mannich reaction of
free secondary amines with aldehydes and silyl ketene acetals.
M. Suginome, L. Uehlin, M. Murakami, J. Am. Chem. Soc.,
2004,
126, 13196-13197.

A highly efficient Mukaiyama aldol reaction is catalyzed by sodium
phenoxide-phosphine oxides as simple homogeneous Lewis base catalysts, which
minimized competing retro-aldol reaction. Various aromatic ketones and
aldimines, aldol and Mannich-type products with an α-quaternary carbon center
were obtained in good to excellent yields.
M. Hatano, E. Takagi, K. Ishihara, Org. Lett., 2007,
9, 4527-4530.

N-Benzyldiphenylphosphinamides are deprotonated at the NCα position
diastereospecifically upon treatment with t-BuLi in diethyl ether at low
temperature. Reaction of the anions with various electrophiles and subsequent cleavage of the P-N linkage affords 1,2-amino alcohols and α-, β-, and γ-amino
acids.
P. O. Burgos, I. Fernández, M. J. Iglesias, S. García-Granda, F. L. Ortiz, Org. Lett., 2008,
10, 537-540.

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.

Sonication of diazo ketones derived from Fmoc-protected amino acids in dioxane
in the presence of silver benzoate and water results in clean formation of the
corresponding β-amino acid derivatives. The degree of racemization was examined
using capillary zone electrophoresis. No substantial epimerization occured
except for phenylglycine.
A. Müller, C. Vogt, N. Sewald, Synlett,
2006, 837-841.

The Arndt-Eistert Reaction in Peptide Chemistry: A Facile Access to
Homopeptides
J. Podlech, D. Seebach, Angew. Chem. Int. Ed.,
1995, 34, 471-472.

A highly enantioselective Mannich reaction with in situ generation of
carbamate-protected imines from stable α-amido sulfones catalyzed by an organic
catalyst provides a concise and highly
enantioselective route converting aromatic and aliphatic aldehydes into
optically active aryl and alkyl β-amino acids.
J. Song, H.-W. Shih, L. Deng, Org. Lett., 2007,
9, 603-606.

A base-catalyzed Michael-type addition of sodium diethyl malonate to N-Boc-α-amidoalkyl-p-tolyl
sulfones in tetrahydrofuran followed by hydrolysis of the adducts in refluxing 6
M aqueous hydrochloric acid affords β3-amino acid hydrochlorides in
high yield and excellent purity.
M. Nejman, A. Śliwińska, A. Zwierzak, Tetrahedron, 2005,
61, 8536-8541.

Efficient carbon-carbon bond formation of N-carbobenzyloxy amines
with 1,3-dicarbonyl compounds at the α-position of nitrogen was established
by a one-pot oxidative Mannich reaction using N-tert-butylbenzenesulfinimidoyl
chloride as an oxidant.
J-I. Matsuo, Y. Tanaki, H. Ishibashi, Org. Lett.,
2006,
8, 4371-4374.

Catalytic asymmetric direct Mannich-type reactions of α-substituted
nitroacetates using a new bench-stable homodinuclear Ni2-Schiff base
complex gave Mannich products in high ee, that serve as precursors for anti-α,β-diamino
acids with an α-tetrasubstituted carbon stereocenter. The Ni complex was also
applicable to direct Mannich-type reactions of malonates and β-keto ester.
Z. Chen, H. Morimoto, S. Matsunaga, M. Shibasaki, J. Am. Chem. Soc., 2008,
130, 2170-2171.

An axially chiral dicarboxylic acid has been applied to a highly
enantioselective Mannich reaction of arylaldehyde N-Boc imines and diazo
compounds as a new class of chiral hydrogen-bonding catalyst.
T. Hashimoto, K. Maruoka, J. Am. Chem. Soc., 2007,
129, 10054-10055.

