Copper-catalyzed reactions of organotitanium reagents. Highly selective SN2′-allylation and conjugate addition
作者:Masayuki Arai、Bruce H. Lipshutz、Eiichi Nakamura
DOI:10.1016/0040-4020(92)80022-8
日期:1992.7
the presence of a catalytic amount of CuI·2LiCl, alkyltitanium (RTi(O-i-Pr)3) and titanate reagents (RnTi(O-i-Pr)5−nLi) undergo highly selective SN2′-alkylation reactions with allylic chlorides and allylic diethylphosphates in high yields. The regioselectivity of the reaction is as high as 99.8%. The reaction proceeds with excellent anti-stereoselectivity with respect to the nucleophile and the leaving
在催化量的CuI·2LiCl存在下,烷基钛(RTi(Oi-Pr)3)和钛酸酯试剂(R n Ti(Oi-Pr)5−n Li)进行高度选择性的S N 2'-烷基化反应,烯丙基氯化物和烯丙基磷酸二乙酯的收率很高。反应的区域选择性高达99.8%。反应的进行具有优异的抗-stereoselectivity相对于亲核试剂和离去基团,表现出高的1,2-反-diastereoselectivity与δ手性烯丙基氯。催化铜试剂还是在Me 3存在下将烷基转移至烯酮的缓和剂氯化硅。烷基钛基催化试剂选择性地与烯丙基磷酸盐而不是与烯酮反应,而在硅活化剂的存在下,它优先与烯酮而不是与磷酸盐反应。Me 2 CuLi和TiCl(Oi-Pr)3的混合物的1 H NMR研究提供了有关试剂组成的信息。