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Full-Text Articles in Physical Sciences and Mathematics
Synthesis Of 5-Azaindoles Via A Cycloaddition Reaction Between Nitriles And Donor-Acceptor Cyclopropanes., Mahmoud M Abd Rabo Moustafa, Brian L Pagenkopf
Synthesis Of 5-Azaindoles Via A Cycloaddition Reaction Between Nitriles And Donor-Acceptor Cyclopropanes., Mahmoud M Abd Rabo Moustafa, Brian L Pagenkopf
Chemistry Publications
A new method for the synthesis of 5-azaindole derivatives is reported. A [3+2] dipolar cycloaddition between nitriles and a 3,4-cyclopropanopiperidine followed by SeO(2) oxidation affords the target compounds in moderate to excellent yields. The divergent nature and cost effectiveness of this method makes it very suitable for combinatorial applications in the pharmaceutical industry.
Synthesis Of Tetrahydroisoquinocarbazoles Via C-2 Alkylation Of Indoles With 2-Alkoxycyclopropanoate Esters., Barbora Bajtos, Brian L Pagenkopf
Synthesis Of Tetrahydroisoquinocarbazoles Via C-2 Alkylation Of Indoles With 2-Alkoxycyclopropanoate Esters., Barbora Bajtos, Brian L Pagenkopf
Chemistry Publications
A concise method for the synthesis of several tetrahydroisoquinocarbazole derivatives is reported, where the core is prepared in six steps from tryptophol in 51% overall yield. The pentacyclic analogs are constructed via a dipolar C-2 alkylation of a 3-substituted indole with a 2-alkoxycyclopropanoate ester and a SmBr(2)-HMPA mediated ketyl-alkene ring closure.
Total Synthesis Of (+/-)-Goniomitine Via A Formal Nitrile/Donor-Acceptor Cyclopropane [3 + 2] Cyclization., Christian L Morales, Brian L Pagenkopf
Total Synthesis Of (+/-)-Goniomitine Via A Formal Nitrile/Donor-Acceptor Cyclopropane [3 + 2] Cyclization., Christian L Morales, Brian L Pagenkopf
Chemistry Publications
The total synthesis of (+/-)-goniomitine has been accomplished in 17 linear steps with 5.2% overall yield starting from commercially available delta-valerolactam. A synthetic highlight includes the first application of a formal [3 + 2] cycloaddition between a highly functionalized nitrile and a donor-acceptor cyclopropane to prepare an indole nucleus. The use of a microwave reactor is shown to greatly improve the reaction times for two steps.
C-2/C-3 Annulation And C-2 Alkylation Of Indoles With 2-Alkoxycyclopropanoate Esters., Barbora Bajtos, Ming Yu, Hongda Zhao, Brian L Pagenkopf
C-2/C-3 Annulation And C-2 Alkylation Of Indoles With 2-Alkoxycyclopropanoate Esters., Barbora Bajtos, Ming Yu, Hongda Zhao, Brian L Pagenkopf
Chemistry Publications
The annulation reaction between various indoles and 2-alkoxycyclopropanoate esters is reported. Both high efficiency and complete stereochemical control were observed in some cases with this annulation process. A single stereocenter on the cyclopropane controls the diastereoselective formation of up to four new stereocenters. A different reaction course was observed with 3-substituted indole substrates, and an intervening C-3 to C-2-migration process arose that gives synthetically useful C-2 alkylation indole products.