当前位置: X-MOL 学术Organometallics › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Cp*Co(CO)I2 as Catalyst for Ortho-C,H Activation at Ferrocene: ODG-Dependent Preference for 2-Mono- or 2,5-Dialkenylation
Organometallics ( IF 2.5 ) Pub Date : 2018-06-26 , DOI: 10.1021/acs.organomet.8b00243
David Schmiel 1 , Robert Gathy 1 , Holger Butenschön 1
Affiliation  

The catalytic ortho-alkenylation at ferrocene has been investigated with Cp*Co(CO)I2 as the catalyst for some nitrogen ortho-directing groups (ODGs). The reaction conditions were optimized starting from 2-ferrocenylpyridine, and a number of terminal arylethynes gave preferentially the 2,5-dialkenylation products in up to 94% yield. In most cases the 2-monoalkenylation products were not obtained, although there are exceptions with formyl- and thioacetyl-substituted arylethynes and ferrocenylethyne. When 1-phenylpropyne was used, the dialkenylation took place with high selectivity. Use of 1-ferrocenylisoquinoline resulted in moderate yields with poor selectivity for the mono- or dialkenylation. With N,N-dimethylferrocenylcarboxamide, however, very high selectivity for monoalkenylation was observed. Products were obtained in up to 90% yield; in only one case the dialkenylation was product observed in trace amounts. All products were characterized spectroscopically, including four crystal structure analyses. The results are explained by the steric hindrance of the N,N-diemethylcarbamoyl ODG when the conformation necessary for a second alkenylation is adopted. In summary, ODGs for the selective cobalt-catalyzed mono- or dialkenylation have been identified.

中文翻译:

Cp * Co(CO)I 2作为二茂铁邻-C,H活化的催化剂:2-单-或2,5-二烯基化反应的ODG依赖性

已经研究了使用Cp * Co(CO)I 2作为某些氮邻位导向基团(ODGs)的催化剂对二茂铁的催化邻位烯基化反应。从2-二茂铁基吡啶开始优化反应条件,许多末端芳基乙炔优先以高达94%的收率得到2,5-二烯基化产物。在大多数情况下,虽然有甲酰基和硫代乙酰基取代的芳炔和二茂铁烯基炔,但没有获得2-单烯基化产物。当使用1-苯基丙炔时,二烯基化反应以高选择性发生。1-二茂铁基异喹啉的使用导致中等收率,对单烯基或二烯基化的选择性差。与NN-然而,观察到二甲基二茂铁基羧酰胺对单烯基化的选择性非常高。获得的产品收率高达90%;在仅一种情况下,观察到痕量的二烯基化产物。所有产品均进行了光谱表征,包括四次晶体结构分析。当采用第二个烯基化所必需的构象时,该结果由NN-二甲基氨基甲酰基ODG的空间位阻来解释。总之,已经鉴定出用于选择性钴催化的单烯基或二烯基的ODG。
更新日期:2018-06-27
down
wechat
bug