Modular Synthesis of Lamellarins via Regioselective Assembly of 3,4,5-Differentially Arylated Pyrrole-2-carboxylates
摘要:
A modular synthesis of lamellarins via 3,4,5-differentially arylated pyrrole-2-carboxylate intermediates has been developed. The key reactions employed are Br-Li exchange-methoxycarbonylation of 2,5-dibromo-1-(tert-butoxycarbonyl)-1H-pyrrole (1) followed by palladium-catalyzed iterative Suzuki-Miyaura coupling of the pyrrole core. The 3,4,5-triarylpyrrole 4 thus synthesized was readily converted to 5,6-saturated lamellarin L (2) and 5,6-unsaturated lamellarin N (3) via lactonization followed by annulation of the pyrrole nitrogen and lateral aromatic ring at C5 using 2-bromoethyl phenyl sulfide or bromoacetaldehyde dimethyl acetal as two-carbon homologation agents. In principle, this strategy allows the production of diverse lamellarins in short steps with high yields using readily accessible arylboronic acids as aromatic modules.
Nickel-Catalyzed Decarboxylative Cross-Coupling of Bicyclo[1.1.1]pentyl Radicals Enabled by Electron Donor–Acceptor Complex Photoactivation
作者:Viktor C. Polites、Shorouk O. Badir、Sebastian Keess、Anais Jolit、Gary A. Molander
DOI:10.1021/acs.orglett.1c01558
日期:2021.6.18
The use of bicyclo[1.1.1]pentanes (BCPs) as para-disubstituted aryl bioisosteres has gained considerable momentum in drug development programs. Carbon–carbon bondformation via transition-metal-mediated cross-coupling represents an attractive strategy to generate BCP–aryl compounds for late-stage functionalization, but these typically require reactive organometallics to prepare BCP nucleophiles on
Discovery of novel and potent heterocyclic carboxylic acid derivatives as protein tyrosine phosphatase 1B inhibitors
作者:Sujay Basu、Uppuleti Viplava Prasad、Dinesh A. Barawkar、Siddhartha De、Venkata P. Palle、Suraj Menon、Meena Patel、Sachin Thorat、Umesh P. Singh、Koushik Das Sarma、Yogesh Waman、Sanjay Niranjan、Vishal Pathade、Ashwani Gaur、Satyanarayana Reddy、Shariq Ansari
DOI:10.1016/j.bmcl.2012.02.070
日期:2012.4
novel heterocyclic carboxylic acid based protein tyrosine phosphatase 1B (PTP1B) inhibitors with hydrophobic tail have been synthesized and characterized. Structure–activity relationship (SAR) optimization resulted in identification of several potent, selective (over the highly homologous T-cell protein tyrosine phosphatase, TCPTP) and metabolically stable PTP1B inhibitors. Compounds 7a, 19a and 19c showed