已经通过吡啶-2-硫代氧羰基(PTOC)竞争动力学方法在单个浓度点上确定了壬基从20种N-杂环卡宾和硼烷(NHC-硼烷)的络合物中提取氢的速率常数。速率常数的范围是从<1×10 4到8×10 4 M -1 s -1。它们几乎不依赖于卡宾核的电子性质,但是存在随着卡宾N取代基尺寸的减小而增加速率常数的趋势。已经鉴定出两种有希望的具有小的N取代基的新试剂(R = Me)。
Cyanoborohydrides are efficient reagents in the reductive addition reactions of alkyl iodides and electron-deficient olefins. In contrast to using tinreagents, the reaction took place chemoselectively at the carbon–iodine bond but not at the carbon–bromine or carbon–chlorine bond. The reaction system was successfully applied to three-component reactions, including radical carbonylation. The rate constant
氰基硼氢化物是烷基碘化物和缺电子烯烃的还原加成反应中的有效试剂。与使用锡试剂相反,该反应在碳碘键上发生化学选择,而在碳溴或碳氯键上没有发生。该反应体系已成功应用于三组分反应,包括自由基羰基化。通过动力学竞争法,在25°C下从氰基硼氢化四丁基铵中伯烷基脱氢的速率常数估计为<1×10 4 M –1 s –1。该值比氢化三丁基锡的值小3个数量级。
PROCESS FOR PRODUCING POLYDIENES
申请人:Bridgestone Corporation
公开号:EP2825574A1
公开(公告)日:2015-01-21
Process For Producing Polydienes
申请人:Bridgestone Corporation
公开号:US20150031845A1
公开(公告)日:2015-01-29
A method for producing a polydiene, the method comprising the steps of (i) forming an active catalyst by combining a lanthanide-containing compound, an alkylating agent, and a halogen source in the substantial absence of an organosulfide; and (ii) polymerizing conjugated diene monomer in the presence of the active catalyst and an organosulfide.
US9650456B2
申请人:——
公开号:US9650456B2
公开(公告)日:2017-05-16
[EN] PROCESS FOR PRODUCING POLYDIENES<br/>[FR] PROCÉDÉ DE FABRICATION DE POLYDIÈNES
申请人:BRIDGESTSONE CORP
公开号:WO2013138270A1
公开(公告)日:2013-09-19
A method for producing a polydiene, the method comprising the steps of (i) forming an active catalyst by combining a lanthanide-containing compound, an alkylating agent, and a halogen source in the substantial absence of an organosulfide; and (ii) polymerizing conjugated diene monomer in the presence of the active catalyst and an organosulfide.