Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by a Titanate Complex with a Chiral Tetradentate Ligand.

نویسندگان

  • Jun Qiu
  • Cheng Guo
  • Xumu Zhang
چکیده

The addition of dialkylzincs to aldehydes is one of the most widely studied carbon-carbon bond-forming reactions. Many systems reported to date use amino alcohols as ligands and zinc complexes as catalysts.1 The asymmetric version of this alkylation reaction can also be catalyzed by chiral titanate complexes2-4 (e.g., TADDOLs2 and chiral sulfonamides3). We have recently studied a titanate complex with tetradentate helical ligand 1 ((1R,2R)-(+)-1,2-bis(3,5-dichloro-2-hydroxybenzenesulfonamido)cyclohexane) for the asymmetric addition of diethylzinc to aldehydes (Figure 1).5 Herein we report the scope of this enantioselective reaction with various substrates. This alkylation approach provides a useful route for the synthesis of some chiral secondary alcohols, especially allylic alcohols,6 and this work contributes to an understanding of the details of this type of reaction.

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عنوان ژورنال:
  • The Journal of organic chemistry

دوره 62 8  شماره 

صفحات  -

تاریخ انتشار 1997