871915-68-3

Upstream product

• 16523-54-9 chlorodicyclohexylphosphane 
• 507241-82-9 2,2^,,6-tribromobiphenyl 
• 1421371-22-3 (R_a)-2',6-dibromobiphenyl-2-ol 
• 911297-81-9 2,6,6'-tribromo-1,1'-biphenyl-2-ol 
• 97038-96-5 2,2’,6,6’-tetrabromobiphenyl 
• 871707-37-8 2,6,6'-tribromo-2'-methoxy-1,1'-biphenyl 
• 873110-78-2 2^,,6-dibromo-2-methoxy-1,1^,-biphenyl 

Relevant academic research and scientific papers

Ligand tailoring: The first modular assembly of atropisomeric biarylbisphosphine ligands

Strategies based on highly selective halogen-metal permutations have been devised and applied enabling the modular assembly of atropisomeric biaryl bisphosphines. After resolution on chiral column, the ligands were tested in benchmark hydrogenation reactions affording good to excellent enantioselectivity. Georg Thieme Verlag Stuttgart.

Bromine-lithium exchange: An efficient tool in the modular construction of biaryl ligands

Regioselective bromine-lithium exchange reactions on polybrominated biaryls enable the modular synthesis of various polysubstituted biphenyls such as bis(dialkylphosphino)-, bis(diarylphosphino)- and dialkyl(diaryl) phosphinobiphenyls. All permutations of

First modular synthesis of dissymmetric biaryldiphosphine ligands allowing tunable steric and electronic effects

The first modular synthesis of a family of C1-symmetric diphosphine ligands is presented. Their synthesis is based on unprecedented highly regioselective halogen/metal interconversions on a common polybrominated biaryl precursor. This methodology allows the functionalization of the ortho- and ortho'-positions of the biaryl core. Diphosphine ligands carrying only one substituent at the 6-position and the two phosphine substituents at the 2- and 2′-position become easily accessible. The two phosphine substituents may be identical (as in compounds 2 and 3) or different (as in compounds 1 and 4). All diphosphines were prepared on gram scale, and the enantiopure ligands were obtained by chromatography of the racemate on a chiral HPLC column. The asymmetric hydrogenation of β-keto esters, acetamidocinnamates and dimethyl itaconate revealed good to excellent asymmetric inductions of up to 99 % ee, and are often close to those of the well-known C2-symmetric MeO-BIPHEP.

A practical transition metal-free aryl-aryl coupling method: Arynes as key intermediates

Upon treatment of various aryllithium intermediates with 1,2-dibromobenzene or 1-bromo-2-iodobenzene, dissymmetrical ortho,ortho′-di-, tri-and even tetrasubstituted bromo- or iodobiaryls become readily available. The crucial steps in all these reactions were the nucleophilic addition of the organolithium precursor to a transient aryne species released from it by β-elimination of a lithium halide and, stabilization of the resulting 2-biaryllithium intermediate by in situ transfer of bromine or iodine from the starting material. This straightforward transition metal-free access to biaryls allows the preparation of highly valuable halobiaryls on a gram scale in excellent yields. These precursors can be subsequently functionalized by highly regioselective halogen/metal permutations into a vast variety of target molecules. This was demonstrated in the synthesis of several mono- and diphosphine ligands.

PROCESS FOR THE PREPARATION OF ASYMMETRICALLY SUBSTITUTED BIARYLDIPHOSPHINES

Provided is a process for the preparation of asymmetrically substituted biaryldiphosphine ligands of the formula, (I) wherein R1 is C1-6-alkyl or C3-10-cycloalkyl optionally substituted with one or more halogen atoms, and R2 and R3 are equal and are C5-10-cycloalkyl or C1-6-alkyl, or R2 is C5-10-cycloalkyl or C1-6-alkyl, and R3 is aryl optionally substituted with one or more substituents selected from the group consisting of halogen atoms, nitro, amino, C1-6-alkyl, C1-6-alkoxy and di-C1-6-alkylamino groups, and each C1-6-alkyl, C1-6-alkoxy, di-C1-6-alkylamino and C5-10-cycloalkyl group in R2 and R3 optionally being substituted with one or more halogen atoms, from 2,2’, 6, 6’-tetra-bromobiphenyl by a sequence of bromine-metal exchanges and subsequent reactions.

PROCESS FOR THE PREPARATION OF ASYMMETRICALLY SUBSTITUTED BIARYLDIPHOSPHINES

Provided is a process for the preparation of asymmetrically substituted biaryldiphosphine ligands of the formula (I), wherein R1 is C1-6-alkyl or C3-10-cycloalkyl optionally substituted with one or more halogen atoms, and R2 and R3 are equal and are selected from the group consisting of aryl, C5-10-cycloalkyl and C1-6-alkyl, or R2 is C5-10-cycloalkyl or C1-6-alkyl, and R3 is aryl optionally substituted with one or more substituents selected from the group consisting of halogen atoms, nitro, amino, C1-6-alkyl, C1-6-alkoxy and di-C1-6-alkylamino groups, and each C1-6-alkyl, C5-10-cycloalkyl, C1-6-alkoxy and di-C1-6-alkylamino group in R2 and R3 optionally being substituted with one or more halogen atoms, from 2,2’,6,6’-tetrabromobiphenyl by a sequence of brominemetal exchanges and subsequent reactions.

Process for the preparation of asymmetrically substituted biaryldiphosphines

Provided is a process for the preparation of asymmetrically substituted biaryldiphosphine ligands of the formula wherein R1 is C1-6-alkyl or C3-10-cycloalkyl optionally being substituted with one or more halogen atoms, and R2 and R3 are independently selected from the group consisting of aryl, C5-10-cycloalkyl and C1-6-alkyl, wherein each aryl moiety is optionally substituted with one or more substituents selected from the group consisting of halogen atoms, nitro, amino, C1-6-alkyl, C1-6-alkoxy and di-C1-6-alkylamino groups, and each C1-6-alkyl, C1-6-alkoxy, di-C1-6-alkylamino and C5-10-cycloalkyl group in R2 and R3 optionally being substituted with one or more halogen atoms, from 2,2',6,6'-tetrabromobiphenyl by a sequence of halogen-metal exchanges and subsequent reactions.