Efficient synthesis of P-chiral biaryl phosphonates by stereoselective intramolecular cyclization

Abstract

COMMUNICATION This journal isA series of P-chiral biaryl phosphonates were efficiently synthesized from diaryl 2-bromo arylphosphonates in high yields (up to 92%) and good enantioselectivities (up to 88% ee) through a palladium-catalyzed asymmetric cyclization with a novel P-chiral biaryl monophosphorus ligand. The P-chiral biaryl phosphonate can be rapidly transformed to both antipodes of a P-chiral dialkyl biaryl monophosphorus structure. The method provides a convenient access to various P-chiral biaryl monophosphines.

Chiral Bifunctional Phosphine‐Carboxylate Ligands for Palladium(0)‐Catalyzed Enantioselective C−H Arylation

“…[10] Related palladium(0)-catalyzed desymmetrizing C(sp 2 )ÀHa rylations generating carbon, [3a,c] phosphorus, [11] or silicon [3b,h] stereocenters have been reported using achiral phosphorus ligand and an achiral base,but such an enantioselective synthesis of 5,6-dihydrophenanthridines has not been described. This structural motif is present in various biologically active substances,inparticular,fluorogenic probes for the detection of reactive oxygen species.…”

Pd-catalyzed enantioselective C–H arylation of phosphinamides with boronic acids for the synthesis of P-stereogenic compounds

“…(1)). Soon after, Duan et al, Liu et al, and Tang et al disclosed independently the asymmetric intramolecular C-H/C-Br arylation of other phosphorus variants through a Pd (0) to Pd (II) cycle, [65][66][67] wherein chiral phosphoramidites or phosphines were employed as effective chiral ligands (Scheme 1, Eq. (2) and (3)).…”

Enantioselective Synthesis of Chiral‐at‐Sulfur 1,2‐Benzothiazines by CpxRhIII‐Catalyzed C−H Functionalization of Sulfoximines

“…Desymmetrization strategies by the selective CÀHf unctionalization of one C(sp 2 )ÀHb ond of enantiotopic aryl groups have been successfully implemented for the generation of stereogenic carbon atoms (Scheme 1). [15,16] Examples of using this concept to create stereogenic phosphorus [17] or silicon atoms [18] are more scarce.R elated methods to access chiral sulfur atoms are,tothe best of our knowledge,elusive, except for as ingle example for chiral sulfoxides reported by Wang and co-workers. [19] On the basis of our findings of creating P-chirality with chiral cyclopentadienyl (Cp x )r ho- dium and iridium catalysts, [17f,h,j] we explored the suitability of these for the generation of sulfoximines with chiral sulfur atoms.H erein, we report an asymmetric annulative C À H functionalization approach of sulfoximines 1 that provides an efficient access to S-chiral 1,2-benzothiazines 3.…”