State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai, 200032, P. R. China.
School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, P. R. China.
Angew Chem Int Ed Engl. 2022 Dec 19;61(51):e202210338. doi: 10.1002/anie.202210338. Epub 2022 Nov 17.
The first copper-catalyzed regiodivergent cyanoboration of internal allenes with B pin (bis(pinacolato)diboron) and NCTS (N-cyano-N-phenyl-p-toluenesulfonamide) derivatives is reported. The β,γ- and α,β-cyanoborylated products were synthesized with high regio- and stereo-selectivity. Computational studies revealed that nucleophilic addition of allylcopper or related intermediates on cyanation reagent is the regio- and stereo-determining step, while transmetalation with B pin is the rate-determining step. The nucleophilic addition step proceeds via inner-sphere mechanism in the Cu /P(o-tol) and Cu /Xantphos (P(o-tol) =tris(o-methylphenyl)phosphine, Xantphos=4,5-bis(diphenylphosphino)-9,9-dimethylxanthene) catalytic systems and via outer-sphere mechanism in the Cu /Xantphos catalytic system, respectively.
首次报道了首例铜催化的内丙二烯与 B pin（频哪醇硼酸酯）和 NCTS（N-氰基-N-苯基对甲苯磺酰胺）衍生物的区域发散氰硼化反应。通过该方法，高区域和立体选择性地合成了β,γ-和α,β-氰基硼化产物。计算研究表明，亲核加成反应中烯丙基铜或相关中间体对氰化试剂的进攻是区域和立体决定步骤，而与 B pin 的转金属步骤是速率决定步骤。亲核加成步骤分别在 Cu /P(o-tol) 和 Cu /Xantphos（P(o-tol)=三(o-甲基苯基)膦，Xantphos=4,5-双（二苯基膦基）-9,9-二甲基氧杂蒽）催化体系中通过内球机制进行，而在 Cu /Xantphos 催化体系中则通过外球机制进行。
