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An Improved and Safer Synthesis of ( R )‐ and ( S )‐4,4′‐Diaminomethyl‐BINAP
Author(s) -
Dayoub Wissam,
FavreReguillon Alain,
Berthod Mikael,
Jeanneau Erwann,
Mignani Gérard,
Lemaire Marc
Publication year - 2012
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201200219
Subject(s) - chemistry , binap , cyanation , yield (engineering) , regioselectivity , halogenation , enantiomer , nuclear magnetic resonance spectroscopy , ionic liquid , cyanide , medicinal chemistry , organic chemistry , enantioselective synthesis , catalysis , metallurgy , materials science
( R )‐ and ( S )‐4,4′‐diaminomethyl‐BINAP were prepared in three steps from enantiomerically pure BINAPO in a global yield of 52 %. A regioselective bromination of BINAPO with NBS in HMimPF 6 gave the desired 4,4′‐dibromo‐BINAPO in quantitative yield, and the recyclability of the ionic liquid was demonstrated. Copper cyanide cyanation of 4,4′‐dibromo‐BINAPO gave the 4,4′‐dicyano‐BINAPO in 70 % yield. Both enantiomers were characterized by NMR spectroscopy and HPLC analysis, and the structures were confirmed by X‐ray crystallography. The cyano and phosphane oxide groups of the resulting 4,4′‐dicyano‐BINAPO were reduced in one step to the corresponding 4,4′‐diaminomethyl‐BINAP by using tetramethyldisiloxane/Ti(O i Pr) 4 in 75 % yield.