Palladium-Catalyzed Acylation Reactions: A One-Pot Diversified Synthesis of Phthalazines, Phthalazinones and Benzoxazinones
A sequential one-pot strategy for the diversified synthesis of phthalazines, phthalazinones and benzoxazinones was presented. This strategy proceeds through [Pd]-catalyzed acylation and nucleophilic cyclocondensation with dinucleophilic reagents. This process was based on direct coupling with simple bench-top aldehydes without the assistance of directing group and without activating the carbonyl group. The process is highly advantageous because it employs simple nitrogen-based nucleophiles, and non-toxic and readily accessible aldehydes as the carbonyl source. Most importantly, the strategy was applied to the one-pot synthesis of PDE-4 inhibitor.
Suchand, Basuli,Satyanarayana, Gedu
p. 2233 - 2246
(2018/06/04)
Ruthenium-Catalyzed Enantioselective Hydrogenation/Lactonization of 2-Acylarylcarboxylates: Direct Access to Chiral 3-Substituted Phthalides
Highly enantioselective tandem hydrogenation/lactonization of various 2-acylarylcarboxylates including 2-aroylarylcarboxylates were realized by using [RuCl(benzene)(S)-SunPhos]Cl as the catalyst under mild reaction conditions. Excellent enantioselectivities (up to 99.6 % ee) and activities (S/C=1000) were obtained. This convenient and practical method enables a direct access to a series of highly optically pure 3-substituted phthalides that are very important molecules as valuable pharmacological compounds and diversified synthons for medicinal chemistry. Moreover, a gram-scale reaction was performed to further demonstrate the practicality of this approach.