An individual ligand for a difficult substrate was identified by screening a small library of nine C2-symmetric chiral diphosphine (MediPhos) ligands in a Pd-catalyzed asymmetric allylic amination. The prepared chiral allylamine was then used as a building block in the synthesis of two new proline-derived dipeptide analogs.
通过在 Pd 催化的不对称烯丙基胺化中筛选由 9 个 C 2对称手性二膦 (MediPhos) 配体组成的小型文库,鉴定了用于困难底物的单个配体。然后将制备的手性烯丙胺用作合成两种新的脯氨酸衍生二肽类似物的结构单元。
Synthesis of Tricyclic Aromatic Compounds by the Intramolecular Pauson−Khand Reaction Promoted by Molecular Sieves<sup>,</sup><sup>1</sup>
Pauson-Khandreactions are carried out with different substituted aromatic enynes, yielding tricyclic cyclopentenones related to natural products such as chromenes. Enynes are easily obtained in a two-step approximation from the corresponding salicylaldehydes. The reaction is promoted by dissolved TMANO (trimethylamine N-oxide) and/or 4 A molecular sieves. This new way of induction for the Pauson-Khand
A new cascade approach has been developed for the one-pot four-step divergent synthesis of polysubstituted benzofurans and 2H-chromenes, featuring a novel cascade aromatic Claisen rearrangement/Meinwald rearrangement/dehydrative or oxidative cyclization. This new method was demonstrated with 39 examples tolerating different substitutions at an epoxide, allylic ether, and aromatic ring, and we showcased
METHOD OF PRODUCING FIVE-CARBON RING-CONTAINING COMPOUND AND FIVE-CARBON RING DERIVATIVE-CONTAINING POLYURETHANE, AND FIVE-CARBON RING DERIVATIVE-CONTAINING POLYURETHANE
申请人:NATIONAL CHUNG SHAN INSTITUTE OF SCIENCE AND TECHNOLOGY
公开号:US20190048123A1
公开(公告)日:2019-02-14
A method of producing a five-carbon ring derivative-containing polyurethane involves introducing a DCPD-derived 5-carbon cyclic compound into a polyurethane material and effectuating polymerization in the presence of a solvent of a low boiling point and low toxicity to produce a five-carbon ring derivative-containing polyurethane of a high molecular weight.
Synthesis of Furo[3,4-<i>c</i>]furans Using a Rhodium(II)-Catalyzed Cyclization/Diels−Alder Cycloaddition Sequence
作者:Albert Padwa、Christopher S. Straub
DOI:10.1021/jo020413d
日期:2003.1.1
acetate, afforded furo[3,4-c]furans in good yield. The reaction proceeds by addition of a rhodium-stabilized carbenoid onto the acetylenic pi-bond to give a vinyl carbenoid that subsequently cyclizes onto the neighboring carbonyl group to produce the furan ring. These furo[3,4-c]furans react with various dienophiles, furnishing anisole derivatives derived by loss of water from the initially formed Diels-Alder