(11bR)-N-Benzyl-N-phenyldinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepin-4-amine
[CAS# 1221901-53-6]

Identification

• Classification: Organic raw materials >> Organic phosphine compound
• Name: (11bR)-N-Benzyl-N-phenyldinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepin-4-amine
• Synonyms: N-Benzyl-N-phenyldinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepin-4-amin
• Molecular Formula: C₃₃H₂₄NO₂P
• Molecular Weight: 497.52
• CAS Registry Number: 1221901-53-6
• SMILES: C1=CC=C(C=C1)CN(C2=CC=CC=C2)P3OC4=C(C5=CC=CC=C5C=C4)C6=C(O3)C=CC7=CC=CC=C76

Properties

• Boiling point: 695.3±48.0 ºC 760 mmHg (Calc.)^*
• Flash point: 374.3±29.6 ºC (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H335
• Precautionary Statements: P261-P305+P351+P338

Discovory and Applicatios

(11bR)-N-Benzyl-N-phenyldinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepin-4-amine is a chiral phosphorus-containing compound widely recognized in the field of asymmetric catalysis. Structurally, it belongs to the class of atropisomeric phosphoramidites, where the rigid dinaphthyl backbone provides the necessary chirality, and the presence of a benzyl and phenyl substituent on the nitrogen atom contributes to its steric and electronic properties. The compound is commonly abbreviated based on its core scaffold, often associated with privileged ligands derived from BINOL-type frameworks.

The discovery of chiral phosphoramidite ligands such as this one emerged in the late 20th century as chemists began designing ligands that could effectively induce asymmetry in transition-metal catalyzed transformations. Building on earlier work involving BINOL-based phosphoric acids and phosphoramidites, researchers developed new variants to expand the scope of enantioselective reactions. The dioxaphosphepin framework in this compound is derived from the condensation of BINOL with phosphorus trichloride or related precursors, followed by functionalization of the phosphorus center to introduce amine substituents. The (11bR) configuration denotes the absolute stereochemistry at the phosphorus-containing ring junction, which is critical for its enantioselective performance.

This compound has found significant utility as a ligand in transition-metal catalysis, particularly in reactions catalyzed by palladium, iridium, and copper complexes. In these applications, the chiral environment provided by the ligand allows for the formation of enantioenriched products with high selectivity. One of the most studied applications includes asymmetric hydrogenation, where complexes formed from this phosphoramidite ligand and iridium precursors have shown high efficiency and enantioselectivity across a variety of substrates.

In addition to hydrogenation, the compound has also been employed in asymmetric allylic substitution reactions. In these transformations, metal–ligand complexes facilitate the replacement of leaving groups in allylic substrates with nucleophiles, generating chiral products with potential utility in pharmaceutical synthesis. The steric and electronic tuning possible with the N-benzyl and N-phenyl substituents allows for fine control over the catalytic environment, which has been essential in optimizing reaction conditions.

The compound's rigid structure and the presence of bulky substituents contribute to its high thermal and chemical stability, making it compatible with a range of solvents and temperatures typically encountered in industrial and laboratory-scale catalysis. Its ease of modification also allows chemists to tailor its properties for specific catalytic systems, enhancing substrate compatibility and enantioselective performance.

Synthetically, (11bR)-N-Benzyl-N-phenyldinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepin-4-amine is prepared from BINOL through a multi-step process. This includes formation of the phosphorus heterocycle, typically involving phosphorus trichloride or phosphorodiamidites, followed by substitution with aniline or N-benzylamine derivatives. The stereochemical integrity is preserved throughout the synthesis, ensuring the production of the desired enantiomer. Purification is typically achieved via recrystallization or chromatographic techniques to remove any racemic or undesired side products.

Due to its role in enantioselective synthesis, the compound is primarily used in the development of pharmaceuticals and fine chemicals where chiral purity is critical. It does not exhibit significant biological activity on its own, but rather functions as an enabling reagent in the synthesis of biologically active compounds. As such, it represents a valuable tool in the repertoire of synthetic organic chemists working in asymmetric catalysis.

This compound, through its well-defined chiral environment and chemical robustness, continues to support advancements in stereoselective synthesis, contributing to the efficient preparation of chiral molecules with high enantiopurity.