The reactions of trialkylboranes or B-alkyl-9-BBN with aryl and 1-alkenyl halides take place readily in the presence of PdCl2(dppf) and sodium hydroxide or methoxide to afford alkylated arenes and alkenes in excellent yields.
Ironing out the kinks: Efficientnew catalytic systems based on iron thiolates are described for the iron‐catalyzed cross‐coupling of alkyl Grignard reagents with alkenylhalides (see scheme). The reaction is highly chemo‐ and stereoselective. With this new procedure, the use of N‐methylpyrrolidone as a co‐solvent is no longer required.
Utilization of a Trimethylsilyl Group as a Synthetic Equivalent of a Hydroxyl Group via Chemoselective C(sp<sup>3</sup>)–H Borylation at the Methyl Group on Silicon
chemoselective C(sp3)–H borylation of the methyl group on silicon. The (borylmethyl)silylgroup formed by C(sp3)–H borylation is treated with H2O2/NaOH, and the resulting (hydroxymethyl)silylgroup is converted into a hydroxyl group by Brook rearrangement, followed by oxidation of the resulting methoxysilyl group under Tamao conditions. An alternative route proceeding through the formylsilyl group formed from
基于铱催化的硅上甲基的化学选择性C(sp 3)-H硼化,可将三甲基甲硅烷基烷烃转化为相应的醇。用H 2 O 2处理由C(sp 3)–H硼化形成的(硼甲基)甲硅烷基然后,在Tamoo条件下,将所得的(羟甲基)甲硅烷基通过布鲁克重排转化为羟基,然后将所得的甲氧基甲硅烷基氧化。还建立了通过Swern氧化通过由(羟甲基)甲硅烷基形成的甲硅烷基甲硅烷基进行的替代途径。该方法适用于取代的三甲基甲硅烷基环烷烃和1,1-二甲基-1-硅环戊烷,以转化成相应的立体定义的环烷基醇和1,4-丁二醇。
Palladium-catalyzed inter- and intramolecular cross-coupling reactions of B-alkyl-9-borabicyclo[3.3.1]nonane derivatives with 1-halo-1-alkenes or haloarenes. Syntheses of functionalized alkenes, arenes, and cycloalkenes via a hydroboration-coupling sequence