AbstractThe multimetallic iridium‐tritin (Ir‐Sn3) complex [Cp*Ir(SnCl3)2{SnCl2(H2O)2}] (1) proved to be a highly effective catalyst towards COH bond activation of γ‐hydroxylactams, leading to a nucleophilic substitution reaction known as the α‐amidoalkylation reaction. Catalyst 1 can be easily synthesized from the reaction of (pentamethylcyclocyclopentadienyl)iridium dichloride dimer {[Cp*IrCl2]2} and tin(II) dichloride (SnCl2). In terms of catalyst loading, reaction conditions and yields of the product formed, 1 is found to be superior compared to classical Lewis acid catalysts. Different carbon (arenes, heteroarenes, allyltrimethylsilane, 1,3‐dicarbonyls) and heteroatom (alcohols, thiols, amides and sulfonamides) nucleophiles have been successfully employed in the intramolecular and intermolecular alkylations, as well as in heterocyclization reactions. In the majority of cases good to excellent yields of 3‐substituted isoindolinones and 5‐substituted pyrrolidin‐2‐ones have been obtained. Besides, the reactions are also atom economical and salt free. It is proposed that the multimetallic Ir‐Sn3 catalyst behaves as a mild and selective Lewis acid to activate the γ‐hydroxylactam towards the formation of the N‐acyliminium ion; the latter being trapped by potent nucleophiles leading to the desired products.magnified image
and practical electrochemical method for selective reduction of cyclicimides has been developed using a simple undivided cell with carbon electrodes at room temperature. The reaction provides a useful strategy for the rapid synthesis of hydroxylactams and lactams in a controllable manner, which is tuned by electric current and reaction time, and exhibits broad substrate scope and high functional group
METHOD FOR PRODUCING SUBSTITUTED POLYCYCLIC PYRIDONE DERIVATIVE AND CRYSTAL OF SAME
申请人:Shionogi & Co., Ltd.
公开号:EP3473629A1
公开(公告)日:2019-04-24
The present invention provides a process for preparing a compound of the formula (II):
wherein R2 is unsubstituted alkyl,
characterized by reacting a compound of the formula (I):
wherein R1 is hydrogen or a protecting group other than unsubstituted alkyl,
with a compound of the formula: R2-OH, wherein R2 is as defined above, in the presence of a sodium salt and/or a magnesium salt.