Facile Synthesis of Structurally Diverse 3,3′-Disubstituted 1,1′-Binaphthyl-2,2′-diamines in Optically Pure Forms

Abstract

A new synthetic route to 3,3'-dihalo BINAMs based on the direct halogenation of H8-BINAM and subsequent rearomatization to the binaphthyl core has been developed. The combination of this new procedure and Pd-catalyzed coupling reactions enabled us to synthesize various 3,3'-disubstituted BINAMs in only three steps starting from H8-BINAM.

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

“…In the synthesis of 3,3′-disubstituted 1,1′-binaphthyl-2,2′diamines, Kano et al brominated partially hydrogenated 1,1′binaphthyl-2,2′-diamine (H 8 -BINAM) (BINAM = 1,1′-binaphthyl-2,2′-diamine) with 2 equiv of NBS in THF at 0 °C for 1 min to give the desired dibromo-H 8 -BINAM (Scheme 207). 736 Using this procedure, they also synthesized another binaphthyl-based diamine where bromination was carried out in high yield in a very short time. 737 Barnes carried out a low-temperature bromination−dehydrobromination process using NBS for the synthesis of various polycyclic aromatic compounds.…”

Hemisquaramide Tweezers as Organocatalysts: Synthesis of Cyclic Carbonates from Epoxides and CO2

“…They were prepared by the Zn­(OTf) 2 -catalyzed reaction of diaminobiaryls (2,2′-diaminobiphenyl ( 8 ), BINAM ( 9 ), or H 8 -BINAM ( 10 )) with an excess amount of diethyl squarate ( 11 ). Compounds 8 , 9 , and 11 are commercially available, and 10 could be easily obtained by reducing 9 . Squaramide 3 was synthesized from 6 and 3,5-bis­(trifluoromethyl)­aniline, and 4 was prepared from 2,2′-bis­(aminomethyl)-1,1′-binaphthyl and 11 (Scheme S2).…”

Direct Interconversion of BINOL and H8-BINOL-Based Chiral Brønsted Acids Using Single-Step Red/Ox Manipulations

“…While the dehydrogenation with Pd/C in refluxing diglyme resulted in decomposition due to dephosphorylation as well as other pathways (entry 1), the oxidations with V 2 O 5 did not result in any reaction, and only starting material 11a was observed (entries 2 and 3). Similarly, the oxidation with DDQ in xylenes at reflux provided no conversion (entry 4), while a similar reaction in 1,4-dioxane resulted in some partial dehydrogenation leading to product 10a (∼25%, entry 5). Finally, the oxidation with DDQ (8 equiv) in refluxing chlorobenzene resulted in clean formation of the desired product 10a in 74% isolated yield.…”