Hydrosilylation of unsaturated compounds with 5-dimethylsilylfurfural diethyl acetal
作者:E. Lukevics、L. E. Demicheva、N. P. Yerchak、Yu. Popelis
DOI:10.1007/bf00697047
日期:1993.10
Hydrosilylation of terminal acetylenes, HC≡CR (R = CMe3,n-C7H15, SiMe3, Ph, COOEt, CH2N(CH2)4, and CH2N(CH2)5) with 5-dimethylsilylfurfural diethyl acetal (1) gives a mixture of products of bothtrans-β- and α-addition. When R = CMe3 or SiMe3, the reaction proceeds regio- and stereospecifically to give only thetrans-β-derivatives. The formation of β-adducts is favored by pronounced electron-donating
末端乙炔、HC≡CR(R = CMe3、n-C7H15、SiMe3、Ph、COOEt、CH2N(CH2)4 和 CH2N(CH2)5)与 5-二甲基甲硅烷基糠醛二乙缩醛 (1) 的氢化硅烷化得到产物混合物反式-β-和α-加成。当 R = CMe3 或 SiMe3 时,反应进行区域定向和立体定向,仅产生反式-β-衍生物。明显的给电子取代基和 Cα 原子的位阻有利于 β-加合物的形成。末端烯烃,H2C=CHR(R = CH2CN、CH2N(CH2)4、CH2N(CH2)5、SiMe3、SiMe(α-呋喃基)2、SiMe2(α-呋喃基)、SiMe2(α-噻吩基)和SiMe2( 5-氯-2-噻吩基)),与硅烷1反应只得到β-加成产物;1与H2C=CHCH2NHC6H13-n的反应得到β-和α-加合物的比例为1.8:1的混合物。