Unusual cycloaddition behavior of 2-substituted norbornadienes with triazolinediones
作者:Waldemar Adam、Luis A. Arias、Ottorino De Lucchi
DOI:10.1016/s0040-4039(00)86841-0
日期:——
2-Chloronorbornadiene affords with 4-phenyltriazolinedione the homocycloadduct (1a) regioselectively as major product, along with small yields of the (2+2)-cycloadduct (2a), the dipolar rearrangement product (3a), and the ring insertion product (4a), while 2-trimethylsilyloxynorbornadiene leads to the ene-product (7c).
PROCESSES FOR MAKING MODULATORS OF CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR
申请人:Vertex Pharmaceuticals Incorporated
公开号:US20210246117A1
公开(公告)日:2021-08-12
The disclosure provides processes for preparing a compound of Formula (I).
该披露提供了制备化合物式(I)的过程。
Synthesis of P-chiral bisphospholane ligands and their transition metal complexes for use as asymmetric hydrogenation catalysts
申请人:——
公开号:US20020087017A1
公开(公告)日:2002-07-04
P-chiral bisphospholane ligands and methods for their preparation are described. Use of metal/P-chiral bisphospholane complexes to catalyze asymmetric transformation reactions to provide high enantiomeric excesses of formed compounds is also described.
CATALYST AND METHOD HAVING SELECTIVITY TO ISOBUTYRALDEHYDE VIA CATALYST INDUCTION
申请人:EASTMAN CHEMICAL COMPANY
公开号:US20130324713A1
公开(公告)日:2013-12-05
Industrially relevant product selectivities and reaction rates are obtained from rhodium catalyzed hydroformylation of propylene via the use of a novel induction period in which the supramolecular ligand assembly, the rhodium precatalyst and an initial substrate are allowed to form a hydroformylation catalyst that is more selective toward branched aldehydes. Upon heating this incubated mixture and addition of propylene, iso-butyraldehyde is obtained in higher concentrations and rates that are otherwise unattainable.
Use of a unique supramolecular assembly of a pyridylphosphine ligand and a metal centered porphyrin complex is shown to give unprecedented selectivities to branched aldehydes via rhodium catalyzed hydroformylation of unsubstituted linear alpha-olefins such as propylene and 1-octene. Increasing the syngas pressure is shown to have a beneficial effect on branched aldehyde selectivity as is increasing the ratio of carbon monoxide to hydrogen used in the hydroformylation reaction.