First synthesis of optically pure α-amino amine as asymmetric amino transfer reagent and its use in asymmetric Mannich reaction

Some of the amino acid chemistry going on in the Laboratory of Amino Acids, Peptides and Proteins

“…However just a few methods allow a smooth cleavage as well as a good template recovery (Kunz et al, 1997, Matsumura andTomita, 1994).…”

“…This chiral auxiliary was designed for the following reasons: (i) The a-acylaminoamine moiety can be smoothly cleaved (dilute acid hydrolysis) yielding the newly formed amine as well as the chiral template (Scheme 15). This auxiliary can be easily regenerated by azide substitution followed by reduction already performed with a closely related piperidine derivative (Matsumura and Tomita, 1994). (ii) The carbonyl group of the acylated amine is favourably situated near the imine nitrogen and is supposed to produce a strong interaction between the oxygen atom and the metal (Zn ++) of the Lewis acid catalyst (Scheme 18).…”

Diastereoselective Imino-Aldol Condensation of Chiral 3-(p-Tolylsulfinyl)-2-furaldimine and Ester Enolates.

“…12-14) Chiral versions of these condensations have also been devised by the use of imines with a chiral auxiliary, [1][2][3][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] chiral ester enolate derivatives, [30][31][32][33][34][35][36] and chiral Lewis acids. [37][38][39][40][41] In the course of our studies on remote asymmetric induction using chiral sulfoxides, we previously reported the lanthanoid triflate-catalyzed Mukaiyama aldol reaction of sulfinyl aldehyde 1 with silyl ketene acetals.…”

“…Of the synthetic routes to b-lactams that have been reported, Lewis acid-promoted [1][2][3] and catalyzed [4][5][6][7][8][9][10][11] condensations of imines with silyl ketene acetals and imino-aldol condensations with ester enolates are powerful methods which involve the efficient construction of stereogenic centers of the b-lactam moiety. [12][13][14] Chiral versions of these condensations have also been devised by the use of imines with a chiral auxiliary, [1][2][3][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] chiral ester enolate derivatives, [30][31][32][33][34][35][36] and chiral Lewis acids. [37][38][39][40][41] In the course of our studies on remote asymmetric induction using chiral sulfoxides, we previously reported the lanthanoid triflate-catalyzed Mukaiyama aldol reaction of sulfinyl aldehyde 1 with silyl ketene acetals.…”

Diastereoselective Cyclopropanation Utilizing a New Chiral N,O‐Acetals Prepared by Electrochemical Oxidation of Carbamates

“…Some optically active cyclopropanes are pharmaceutically interesting compounds.' Thus much effort has so far been devoted to development of methods for a stereoselective cyclopropanation as exemplified by a cyclopropanation of olefins possessing chiral carbons in the parent molecule 3 or a cyclopropanation using chiral metal catalysts." However, facile methods for allyl alcohols have not always been available.…”