Pd触媒を用いた2位に表置換基を持つシクロヘキセン誘導体の触媒的不斉合成および天然物合成への利用

抄録

The asymmetric synthesis of 2-arylcyclohexene derivatives was realized via π-allylpalldium complex generated from 2-arylcyclohexenol derivatives, Pd (0), and (S) -BINAPO. Using this method, (-) -mesembrine, (-) -mesembrane, (+) -crinamine, (-) -haemanthidine and (+) -pretazetine were synthesized. Subsequently, we planed to synthesize indole alkaloids as a chiral form using this method. Thus, the novel procedure for the synthesis of indole skeleton was developed. Treatment of cyclohexenol derivative having the silyloxymethyl group at the 2-position with N-tosyl-ο-bromoaniline in the presence of Pd₂dba₃·CHCl₃ and (S) -BINAPO gave cyclohexenylamine derivative with 84% ee in 76% yield. The siloxymethyl group was converted into the cyanomethyl group and the resulting compound was treated with Pd (OAc) ₂ and PMe₂Ph to give indole derivative. From this compound, we succeeded in the total synthesis of (-) -dehydrotubifoline and (-) -tubifoline.