38691-92-8Relevant academic research and scientific papers
Method for synthesizing benzophenanthridine and protoberberine alkaloids through modular diversity regulation and control
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Paragraph 0481-0486, (2021/05/29)
The invention discloses a method for synthesizing benzophenanthridine and protoberberine alkaloids through modular diversity regulation and control. The method comprises the following steps: improving a substituent group of a high-iodine salt leaving group, generating pyridine alkyne under the action of relatively mild potassium tert-butoxide, and carrying out [4 + 2] cycloaddition reaction on the pyridine alkyne and diene to obtain polysubstituted isoquinoline ring precursor compounds. Ring opening and aromatization of the isoquinoline ring precursor are realized by developing a novel iridium-catalyzed cross-coupling method, polysubstituted isoquinoline ring compounds with connecting capacity are efficiently synthesized, and then the polysubstituted isoquinoline ring compounds are coupled with a high-activity polysubstituted cyclic boric acid to obtain 3-aryl isoquinoline high-grade intermediates. Through application of two different chemical principles, regulation and control of the 3-aryl isoquinoline high-grade intermediates are realized, and benzophenanthridine and protoberberine alkaloids are modularly, diversely and efficiently synthesized.
A General, Concise Strategy that Enables Collective Total Syntheses of over 50 Protoberberine and Five Aporhoeadane Alkaloids within Four to Eight Steps
Zhou, Shiqiang,Tong, Rongbiao
supporting information, p. 7084 - 7089 (2016/05/19)
A concise, catalytic, and general strategy that allowed efficient total syntheses of 22 natural 13-methylprotoberberines within four steps for each molecule is reported. This synthesis represents the most efficient and shortest route to date, featuring three catalytic processes: CuI-catalyzed redox-A3 reaction, Pd-catalyzed reductive carbocyclization, and PtO2-catalyzed hydrogenation. Importantly, this new strategy to the tetracyclic framework has also been applied to the collective concise syntheses of >30 natural protoberberines (without 13-methyl group) and five aporhoeadane alkaloids.
