Convenient asymmetric synthesis of both enantiomers of 3,4-disubstituted 3,4-dihydro-1,4-benzoxazin-2-ones

<p>Both enantiomers of <i>N</i>-substituted 3-arylated 3,4-dihydro-1,4-benzoxazin-2-ones were conveniently synthesized up to 93:7 er based on the dynamic kinetic resolution of either (<i>R</i>)-pantolactone- or l-mandelate-derived α-bromo arylacetates in nucleophilic substitution with <i>N</i>-alkylated 2-aminophenols.</p

Asymmetric Synthesis of <i>trans</i>-2,3-Disubstituted Indoline Derivatives

A novel method for asymmetric synthesis of <i>trans-</i>2,3-disubstituted indolines has been developed. The strategy involves the (−)-sparteine-mediated electrophilic substitution of 2-benzyl <i>N</i>-pivaloylaniline with aromatic or α,β-unsaturated aldehydes and subsequent intramolecular nucleophilic substitution. The simple protocol for two-step process can produce highly enantioenriched indolines <b>3a</b>–<b>o</b> up to 98:2 er

[M(<i>rac</i>-<i>N</i>-benzyl Asp)(H₂O)] (M = Co, Ni): Noncentrosymmetric Coordination Polymeric Chains with Racemic Chiral Ligands

The hydrothermal reaction of fumaric acid, benzylamine, and metal salts yielded M­[(<i>rac</i>-<i>N</i>-benzyl-Asp)­(H₂O)] (M = Co, Ni), <b>1</b> and <b>2</b>, and Ni­[(<i>rac</i>-<i>N</i>-benzyl-Asp)­(H₂O)₃]·H₂O <b>3</b>. Under mild hydrothermal conditions, Michael addition of benzylamine to fumaric acid led to the formation of a racemic mixture of <i>N</i>-benzyl aspartic acid enantiomers. The noncentrosymmetric structures of <b>1</b> and <b>2</b> consist of one-dimensional polymeric chains in which metal cations are bridged by d- and l-<i>N</i>-benzyl aspartate anions alternating along the chain. The centrosymmetric structure of <b>3</b> is composed of discrete Ni­[(<i>rac</i>-<i>N</i>-benzyl-Asp)­(H₂O)₃] units that are connected by hydrogen bonds into layers. The single layers are homochiral but are hydrogen bonded to similar homochiral layers that contain the <i>N</i>-benzyl aspartate with the opposite handedness. Compounds <b>1</b> and <b>2</b> showed second harmonic generation (SHG), and their magnetic and thermodynamic properties are described

[M(<i>rac</i>-<i>N</i>-benzyl Asp)(H₂O)] (M = Co, Ni): Noncentrosymmetric Coordination Polymeric Chains with Racemic Chiral Ligands

The hydrothermal reaction of fumaric acid, benzylamine, and metal salts yielded M­[(<i>rac</i>-<i>N</i>-benzyl-Asp)­(H₂O)] (M = Co, Ni), <b>1</b> and <b>2</b>, and Ni­[(<i>rac</i>-<i>N</i>-benzyl-Asp)­(H₂O)₃]·H₂O <b>3</b>. Under mild hydrothermal conditions, Michael addition of benzylamine to fumaric acid led to the formation of a racemic mixture of <i>N</i>-benzyl aspartic acid enantiomers. The noncentrosymmetric structures of <b>1</b> and <b>2</b> consist of one-dimensional polymeric chains in which metal cations are bridged by d- and l-<i>N</i>-benzyl aspartate anions alternating along the chain. The centrosymmetric structure of <b>3</b> is composed of discrete Ni­[(<i>rac</i>-<i>N</i>-benzyl-Asp)­(H₂O)₃] units that are connected by hydrogen bonds into layers. The single layers are homochiral but are hydrogen bonded to similar homochiral layers that contain the <i>N</i>-benzyl aspartate with the opposite handedness. Compounds <b>1</b> and <b>2</b> showed second harmonic generation (SHG), and their magnetic and thermodynamic properties are described

[M(<i>rac</i>-<i>N</i>-benzyl Asp)(H₂O)] (M = Co, Ni): Noncentrosymmetric Coordination Polymeric Chains with Racemic Chiral Ligands

The hydrothermal reaction of fumaric acid, benzylamine, and metal salts yielded M­[(<i>rac</i>-<i>N</i>-benzyl-Asp)­(H₂O)] (M = Co, Ni), <b>1</b> and <b>2</b>, and Ni­[(<i>rac</i>-<i>N</i>-benzyl-Asp)­(H₂O)₃]·H₂O <b>3</b>. Under mild hydrothermal conditions, Michael addition of benzylamine to fumaric acid led to the formation of a racemic mixture of <i>N</i>-benzyl aspartic acid enantiomers. The noncentrosymmetric structures of <b>1</b> and <b>2</b> consist of one-dimensional polymeric chains in which metal cations are bridged by d- and l-<i>N</i>-benzyl aspartate anions alternating along the chain. The centrosymmetric structure of <b>3</b> is composed of discrete Ni­[(<i>rac</i>-<i>N</i>-benzyl-Asp)­(H₂O)₃] units that are connected by hydrogen bonds into layers. The single layers are homochiral but are hydrogen bonded to similar homochiral layers that contain the <i>N</i>-benzyl aspartate with the opposite handedness. Compounds <b>1</b> and <b>2</b> showed second harmonic generation (SHG), and their magnetic and thermodynamic properties are described