A Highly Reusable Rhodium Catalyst-Organic Framework for the Intramolecular Cycloisomerization of 1,6-Enynes
摘要:
The intramolecular cycloisomerization of 1,6-enynes in 95-99% ee is reported using an immobilized Rh catalyst-organic framework synthesized from alternating ring-opening metathesis polymerization (altROMP) assembly. The framework was reused up to seven times, and it was used in high turnover number (TON) batch reactions. The catalyst provided the highest TONs to date (up to 890) for the cycloisomerizations, with catalyst loadings ranging from 0.2 to 0.06 mol %.
On the Enantioselective Rhodium‐Catalyzed Enyne Cyclization
作者:A. Stephen K. Hashmi、Patrick Haufe、Andreas Rivas Nass
DOI:10.1002/adsc.200303086
日期:2003.11
Several chiral ligands were tested in the enantioselectiverhodium-catalyzed enyne cyclization, but none gave results comparable to the BINAP ligand. Among the tested catalyst precursors the soon to be commercially available [(COD)Rh(H2O)2]CF3SO3 complex is an interesting alternative to the [(COD)RhCl]2 because it did not need the activation with silver ions. A new stereogenic and 1,2-disubstituted
在对映体选择性铑催化的烯炔环化中测试了几种手性配体,但没有一个结果可与BINAP配体相比。在经过测试的催化剂前体中,即将上市的[(COD)Rh(H 2 O)2 ] CF 3 SO 3络合物是[(COD)RhCl] 2的有趣替代品,因为它不需要用银进行活化。离子。在产物12中形成了新的立体异构和1,2-二取代的双键,证明后者具有(E)-构型。在较高温度下观察到一种新产物1,3-二烯16。在(E在起始材料中)-构型的双键,反应完全失败。
HETEROGENEOUS RHODIUM METAL CATALYSTS
申请人:Bergens Steven H.
公开号:US20130053576A1
公开(公告)日:2013-02-28
Novel polymeric rhodium catalysts having repeating subunits of Formula (I), wherein R
1
-R
8
, X, A, m, n and p are as defined in the application, are described along with methods of using these catalysts, as well as precursors therefor, in the chemical synthesis transformations.
<i>Tropos</i> or <i>Atropos</i> Nature of Rhodium Complexes Bearing a Tetrakis(phosphanyl)terphenyl Ligand: Highly Enantioselective Catalysis of Ene-Type Cyclization
作者:Koichi Mikami、Shohei Kataoka、Kohsuke Aikawa
DOI:10.1021/ol052281r
日期:2005.12.1
TETRAPHOS-Rh complex is increased by association of DABN. In contrast, the diamine-free complex is chirally more stable than the BIPHEP counterpart. The higher levels of enantioselectivity in ene-typecyclization of 1,6-enynes can thus be achieved even at room temperature by the diamine-free TETRAPHOS-Rh complex.
Chiral aminoalcohol NOBIN for instantaneous chirality control of racemic but tropos BIPHEP–Rh(I)-complexes: highly enantioselective ene-type cyclization of 1,6-enynes catalyzed by the Rh(I)-complexes without use of acid
instantaneously even at room temperature. The BIPHEP–Rh/NOBIN complex thus controlled can be used as an asymmetric catalyst to give higher enantioselectivity (up to 98% ee) and yield in ene-typecyclization of 1,6-enynes without use of acid.