A Micellar Catalysis Strategy for Suzuki–Miyaura Cross-Couplings of 2-Pyridyl MIDA Boronates: No Copper, in Water, Very Mild Conditions
摘要:
Suzuki-Miyaura (SM) cross-couplings of 2-pyridyl MIDA boronates can be successfully carried out in the complete absence of copper by attenuation of the Lewis basicity associated with the pyridyl nitrogen using selected substituents (e.g., fluorine or chlorine) on the ring. This strategy imparts additional synthetic options compared with existing approaches based on the use of Lewis acids or N-oxides. Thus, access to highly valued 2-substituted pyridyl rings via an initial Suzuki-Miyaura coupling can be followed by dehalogenation, SNAr reactions, or a second SM coupling to arrive at 2,6-disubstituted pyridyl arrays, all run in a single pot, enabled by micellar catalysis in water. Accessing targets within drug-like space is demonstrated in a four-step, one-pot sequence. Computational data suggest that the major role being played by electron-withdrawing substituents in promoting these cross-couplings without the need for copper is to slow the rates of protodeboronation of intermediate 2-pyridylboronic acids.
Transition-Metal-Free Decarboxylative Arylation of 2-Picolinic Acids with Arenes under Air Conditions
作者:Xitao Zhang、Xiujuan Feng、Chuancheng Zhou、Xiaoqiang Yu、Yoshinori Yamamoto、Ming Bao
DOI:10.1021/acs.orglett.8b03043
日期:2018.11.16
transition-metal-free, and direct decarboxylative arylation of 2-picolinic acids with simple arenes is described. The oxidativedecarboxylative arylation of 2-picolinic acids with arenes proceeds readily via N-chloro carbene intermediates to afford 2-arylpyridines in satisfactory to good yields under transition-metal-free conditions. This new type of decarboxylative arylation is operationally simple
Rhodium‐Catalyzed C−H Methylation and Alkylation Reactions by Carbene‐Transfer Reactions
作者:Claire Empel、Sripati Jana、Tim Langletz、Rene M. Koenigs
DOI:10.1002/chem.202104321
日期:2022.2.24
diazoalkanes and their compatibility in this C-H functionalization reaction. With these findings, suitable reaction conditions for the C-H methylation reactions were quickly identified by using highly reactive TMS diazomethane and C-H alkylationreactions with donor/acceptor diazoalkanes, which is applied to a broad scope on alkylationreactions of 2-aryl pyridines with TMS diazomethane and donor/acceptor
[EN] N-TERMINALLY MODIFIED GLP-1 RECEPTOR MODULATORS<br/>[FR] MODULATEURS DES RECEPTEUR GLP-1 A MODIFICATION N-TERMINALE
申请人:BRISTOL MYERS SQUIBB CO
公开号:WO2006127948A2
公开(公告)日:2006-11-30
[EN] The subject matter described herein provides novel human glucagon-like peptide-1 (GLP-1) receptor modulators that have biological activity similar or superior to native GLP-1 peptide and thus are useful for the treatment or prevention of diseases or disorders associated with GLP activity. The described compounds include chemically modified peptides that not only stimulate insulin secretion in type II diabetics, but also produce other beneficial insulinotropic responses. These synthetic peptide GLP-1 receptor modulators exhibit increased stability to proteolytic cleavage making them ideal therapeutic candidates for oral or parenteral administration. The disclosed and claimed peptides show desirable pharmacokinetic properties and desirable potency in efficacy models of diabetes. [FR] L'invention concerne de nouveaux modulateurs des récepteurs du peptide 1 de type glucagon (GLP-1) humain présentant une activité biologique similaire ou supérieure à celle du peptide natif GLP-1, ces modulateurs étant utilisés pour traiter ou prévenir les maladies et les troubles associés à l'activité de GLP. Les composés décrits comprennent des peptides chimiquement modifiés qui non seulement stimulent la sécrétion d'insuline chez les diabétiques de type II mais produisent également d'autres réponses insulinotropiques bénéfiques. Ces modulateurs des récepteurs du peptide synthétique GLP-1 possèdent une stabilité accrue par rapport à un clivage protéolytique, ce qui fait d'eux des candidats thérapeutiques idéaux pour une administration orale ou parentérale. Les peptides décrits présentent des propriétés pharmacocinétique et une puissance désirées dans des modèles d'efficacité de diabète.