Synthesis, Properties, and Hydroboration Activity of the Highly Electrophilic Borane Bis(pentafluorophenyl)borane, HB(C<sub>6</sub>F<sub>5</sub>)<sub>2</sub><sup>1</sup>
作者:Daniel J. Parks、Warren E. Piers、Glenn P. A. Yap
DOI:10.1021/om980673e
日期:1998.12.1
bis(pentafluorophenyl)borane, 1, are described. A three-step procedure uses the −C6F5 transfer agent Me2Sn(C6F5)2 to produce the chloroborane ClB(C6F5)2, which is subsequently converted to 1 by treatment with a silane, and proceeds with an overall yield of 62%. Alternatively, 1 can be made in 69% yield from B(C6F5)3 and Et3SiH by heating the two reagents at 60 °C for 3 days in benzene. Borane 1 is dimeric in
描述了两种可靠且有效的途径制备双(五氟苯基)硼烷1。三步过程使用-C 6 F 5转移剂Me 2 Sn(C 6 F 5)2生成氯硼烷ClB(C 6 F 5)2,随后将其通过硅烷处理转化为1,收益率为62%。或者,可以从B(C 6 F 5)3和Et 3以69%的收率制得1通过在苯中在60°C下加热两种试剂3天来实现SiH。硼烷1是固态的二聚体,如通过X射线晶体学分析所确定的。然而,在芳族溶剂中,存在可检测量的单体硼烷(二聚物:单体之比≈4.5∶1)。二聚体易于与单体解离,再加上硼烷的高亲电性,使得1在芳族溶剂中成为非常活泼的加氢硼化试剂。在供体溶剂(例如四氢呋喃)中不会进行硼氢化。多种烯烃的调查和炔底物表明,1氢硼酸盐具有与常用试剂(如9-BBN)相当的区域选择性和化学选择性,但速率要快得多。试剂的第二个独特特征是在烯烃加氢硼化产物中发生硼烷基迁移的设备。该性质可用于获得硼氢化的热力学产物,其
Reactions of stabilized criegee intermediates from the gas-phase reactions of O3 with selected alkenes
作者:Jillian Baker、Sara M. Aschmann、Janet Arey、Roger Atkinson
DOI:10.1002/kin.10022
日期:2002.2
thermalized Criegee intermediates in these reactions makes observation of α-hydroxyhydroperoxides from these reactions less likely than from the 1-octene and trans-7-tetradecene reactions. Quantifications of 2,7-octanedione from the 1,2-dimethyl-1-cyclohexene reactions and of pinonaldehyde from the α-pinene reactions were made by gas chromatographic analyses during reactions with cyclohexane and with 2-butanol
CONVENIENT SYNTHESES OF ALKYL THIOCYANATES AND ALKYL SELENOCYANATES FROM STERICALLY HINDERED OLEFIN VIA HYDROBORATION. SELECTIVE REACTIONS OF SECONDARY OR TERTIARY ALKYL GROUP IN MIXED TRIALKYLBORANES WITH FERRIC THIOCYANATE OR FERRIC SELENOCYANATE
作者:Akira Arase、Yuzuru Masuda
DOI:10.1246/cl.1976.1115
日期:1976.10.5
Mixed trialkylboranes, prepared by the successive reactions of BH3 in THF with a sterically hindered internal olefin and a terminal olefin, reacted with either aqueous ferricthiocyanate or aqueous ferric selenocyanate to give corresponding secondary or tertiary alkyl thiocyanates or selenocyanates selectively.
作者:Takashi Yamamoto、Tsunehiro Tanaka、Takuzo Funabiki、Satohiro Yoshida
DOI:10.1021/jp980675c
日期:1998.7.1
Siliceous FSM-16 possesses acid sites to catalyze but-l-ene isomerization to produce but-2-ene (cis/trans = 1.4-1.7) at 323 K and 2,6,6-trimethylbicyclo[3.1.1]hept-2-ene (alpha-pinene) isomerization at 303 K. Catalytic activity was dependent upon heat treatment and reached a maximum at 673 K. The maximum acid strength was invariably H-0 = -3.0 independent of the pretreatment temperatures. The acidity was much reduced by calcination at higher temperatures, but restored by water treatment at 353 K as long as the FSM-16 retained its structure.
TRIPEPTIDE BORONIC ACID OR BORONIC ESTER, PREPARATIVE METHOD AND USE THEREOF