使用三(五氟苯基)硼烷(B(C 6 F 5)3)作为催化剂的无金属氢化硅烷化使得α-二酮和双(硅烷)单体能够在环境条件下快速聚合,从而获得高分子量的聚(甲硅烷基醚) s(PSE)。带有不同主链和侧链官能团的多种可商购的单体被证明与这些无金属条件相容。值得注意的是,这些聚(甲硅烷基醚)的热性质是高度可调的,在各种情况下都可获得新颖的半结晶材料。这些聚(甲硅烷基醚)材料可作为具有设计降解曲线和结晶度的材料的通用平台。
Silane-Controlled Diastereoselectivity in the Tris(pentafluorophenyl)borane-Catalyzed Reduction of α-Diketones to Silyl-Protected 1,2-Diols
作者:Miranda K. Skjel、Adrian Y. Houghton、Andrea E. Kirby、Daniel J. Harrison、Robert McDonald、Lisa Rosenberg
DOI:10.1021/ol902451h
日期:2010.1.15
B(C6F5)3-catalyzed bis(hydrosilylation) of α-diketones can give high diastereomeric excess of either meso/anti (small silanes and disilane reagents) or dl/syn (bulky silanes) silyl-protected 1,2-diols. This easily tuned diastereoselectivity is rationalized based on the classic Felkin−Anh model applied to a mechanism relying on Si−H abstraction by the electrophilic borane reagent.
B(C 6 F 5)3催化的α-二酮双(氢硅烷化)反应可得到非对映异构体过量的内消旋/反(小硅烷和乙硅烷试剂)或dl / syn(大硅烷)甲硅烷基保护的1,2-二醇。这种易于调整的非对映选择性是根据经典Felkin-Anh模型合理化的,该模型应用于依赖亲电子硼烷试剂从Si-H提取的机制。
Reaction of Aromatic Carbonyl Compounds with Silylborane Catalyzed by Au Nanoparticles: Silylative Pinacol-type Reductive Dimerization via a Radical Pathway
after initial activation of silylborane by Au nanoparticles and addition to the carbonyl functionality of an aromatic aldehyde or ketone, an aryl silyloxy radical is generated from the collapse of the intermediate adduct, which then dimerizes through a chain process. The silyloxy radical was almost quantitatively trapped in the presence of TEMPO.