L'intermediaire de reaction un metallocyclobutane mono ou dissubstitue par un groupemethyl n'a pas de configurationpreferentielle pour le monosubstitue et preferrede prendre la configuration trans pour le dissubstitue
Mild and Selective Deuteration and Isomerization of Alkenes by a Bifunctional Catalyst and Deuterium Oxide
摘要:
H/D exchange is achieved at allylic positions of alkenes using D2O in acetone and alkene isomerization catalyst 1, which features a bifunctional imidazolylphosphine. The basic nitrogen of the latter is thought to deprotonate an alkene substrate coordinated to the CpRu center; at this stage the protonated nitrogen could undergo H/D exchange with deuterium oxide. An exceptional degree of deuteration is achieved at positions accessible to isomerization, with a high degree of control. Using biphasic settings one can literally wash out reactive protons on the substrate without using organic solvents.
catalyst the stereo-selective formation of cis- and trans-[2H4]but-2-ene is observed in the metathesis of equimolar mixtures of cis-[2H0]- and -[2H8]but-2-ene, and trans-[2H0]- and -[2H8]-but-2-ene, respectively; the yields of cis- and trans-but-2-ene from reactions of the corresponding pent-2-ene isomers are in good agreement, but metathesis of propene selectively yields trans-but-2-ene.
以MoO x / β- TiO 2为催化剂,在顺式-[ 2 H 0 ]-和-的等摩尔混合物复分解中观察到顺式-和反式-[ 2 H 4 ]丁-2-烯的立体选择性形成。[ 2 H 8 ]丁-2-烯和反式-[ 2 H 0 ]-和-[ 2 H 8 ]-丁-2-烯;顺式和反式的产量来自相应的戊-2-烯异构体的反应生成的-丁-2-烯非常吻合,但是丙烯的复分解选择性地产生了反式-丁-2-烯。
Synthesis of 2-Butene-2,3-<i>d</i>
<sub>2</sub>and 2-Butene-1,1,1,4,4,4-<i>d</i>
<sub>6</sub>