CATALYTIC CONJUGATE ADDITION PROMOTED BY THE COPPER(I)-MONOTHIOBINAPHTHOL SYSTEM .2. OPTIMAL LIGAND SYNTHESIS AND INITIAL CATALYTIC RESULTS

Both racemic and (R(a))-1,1'-bi-2-naphthol react with Bu(2)SnO to prov ide an O,O-stannylene acetal which opens with Me(2)NC(S)Cl or RC(O)Cl [R = Ph, CCl3, OPr, 1-C10H7, 2-C10H7, SMe, CH2Cl and (-)-menthyl] to f ashion monoacylated derivatives. Two of the products, imethylthiocarba moyloxy)-2-hydroxy-1,1'-binaphthyl 6 and 2'-[(1R,3S,5R)-menthylcarbony loxyl]-1,1'-binaphtyl 14, have been crystallographically characterised . The former is converted to -2'-(N,N-dimethylthiocarbamoyloxy)-1,1'-b inaphthyl 15 with Me(2)NC(O)Cl. This compound is directly available fr om 1,1'-bi-2-naphthol via a one-pot sequential reaction with Me(2)NC(S )Cl and Me(2)NC(O)Cl under NEt(3)-DMAP catalysis. Thermolysis of 15 fo llowed by hydrolysis provides an efficient preparation of 2-hydroxy-2' -mercapto-1,1'-binaphthyl 3 (monothiobinaphthol). In the presence of [ Cu(MeCN)(4)]BF4, 3 leads to a highly efficient catalyst for the 1,4-ad dition of BuLi and RMgX (R = Me, Bu, Ph; X = Cl, Br) to cyclic enones.