827340-35-2Relevant academic research and scientific papers
Total synthesis of calothrixins A and B via oxidative radical reaction of cyclohexenone with aminophenanthridinedione
Xu, Su,Nguyen, Thao,Pomilio, Irene,Vitale, Maria C.,Velu, Sadanandan E.
, p. 5928 - 5933 (2014)
Bioactive indolo[3,2-j]phenanthridine alkaloids, calothrixin B and its N-oxide derivative calothrixin A have been synthesized via an oxidative free radical reaction. Calothrixin B is generated from the commercially available 2,4,5-trimethoxybenzaldehyde in only seven steps. The key step in this synthesis is the Mn(OAc)3 mediated oxidative free radical reaction of 9-(benzylamino)phenanthridine-7,10-dione with cyclohexenone to form 12-benzyl-12H-indolo[3,2-j]phenanthridine-7,13-dione.
Formal total synthesis of calothrixin B and its N-benzyl analogues
Ramkumar, Nagarajan,Nagarajan, Rajagopal
, p. 87838 - 87840 (2015)
A formal total synthesis of calothrixin B and its N-benzyl analogues has been accomplished from (2-chlorophenyl)boronic acid, 8-bromophenanthridine-7,10-dione and benzylamines. The synthesis involves Suzuki cross-coupling and copper-catalyzed domino reactions to generate N-benzylcalothrixins in good to moderate yields.
A General Carbazole Synthesis via Stitching of Indole-Ynones with Nitromethanes: Application to Total Synthesis of Carbazomycin A, Calothrixin B, and Staurosporinone
Singh, Shweta,Samineni, Ramesh,Pabbaraja, Srihari,Mehta, Goverdhan
, p. 3372 - 3376 (2019/05/10)
A new, one-pot domino benzannulation reaction between indole-3-ynones and various nitromethane derivatives has been explored for a general entry to diversely functionalized carbazole frameworks (28 examples). The scope of this new benzannulation has been
Total Syntheses of Arcyriaflavin A and Calothrixin B Using 2,2′-Bisindole-3-acetic Acid Derivative as a Common Intermediate
Lee, Sungjong,Kim, Kyung-Hee,Cheon, Cheol-Hong
, p. 2785 - 2788 (2017/06/07)
A new protocol for the synthesis of 2,2′-bisindole-3-acetic acid derivatives from aldimines derived from 2-aminocinnamic acid derivatives and indole-2-carboxaldehyde was developed via a cyanide-catalyzed imino-Stetter reaction. With this protocol, the divergent total syntheses of arcyriaflavin A, a representative indolocarbazole natural product, and calothrixin B, a representative indolo[3,2-j]phenanthridine natural product, were completed using a 2,2′-bisindole-3-acetic acid derivative as the common intermediate.
Total synthesis of calothrixin B via sequential Sonogashira coupling/copper-catalyzed oxidative cyclization
Ramkumar, Nagarajan,Nagarajan, Rajagopal
, p. 11046 - 11051 (2015/11/25)
A total synthesis of the antimalarial indolo[3,2-j]phenanthridine alkaloid calothrixin B is reported. The key intermediate, ketoester 11, was assembled using sequential Sonogashira coupling and intra/intermolecular fashioned copper-catalyzed oxidative cyclization reactions.
Diversity-Oriented Synthesis of Calothrixins and Ellipticines
Dethe, Dattatraya H.,Murhade, Ganesh M.
, p. 6953 - 6962 (2016/02/19)
The divergent synthesis of calothrixins and ellipticines has been accomplished by utilising the one-pot formation of o-diacylarenes as a key intermediate through rearrangement of o-hydroxy ketone monoacyl hydrazones by lead tetraacetate mediated oxidation. The divergent synthesis of calothrixins and ellipticines has been accomplished by utilising the one-pot formation of o-diacylarenes as a key intermediate through rearrangement of o-hydroxy ketone monoacyl hydrazones by lead tetraacetate mediated oxidation.
Unexpected observations during the total synthesis of calothrixin B-sodium methoxide as a source of hydride
Bhosale, Shrikar M.,Momin, Aadil A.,Kunjir, Shrikant,Rajamohanan,Kusurkar, Radhika S.
, p. 155 - 162 (2014/01/06)
During the total synthesis of calothrixin B, various novel and unexpected results were noticed such as cleavage of C-N bond in imine using sodium cyanoborohydride, sodium methoxide as a hydride source for reduction, deformylation in the presence of bromine, and deacylation using ceric ammonium nitrate (CAN). A detailed mechanism has been proposed for the unexpected results and a few of them are generalized. Temperature dependent NMR studies have been carried out for confirmation of the structure of one of the intermediates in the synthetic sequence.
An efficient total synthesis of calothrixin B
Bhosale, Shrikar M.,Gawade, Rupesh L.,Puranik, Vedavati G.,Kusurkar, Radhika S.
, p. 2894 - 2896 (2012/07/27)
An efficient synthesis of calothrixin B (2) is demonstrated starting from 9H-carbazol-4-ol, having two one-pot reaction sequences as key steps. As a novel observation, DMF-methanol was shown to be a hydride donor for reduction of aldehyde to alcohol. Unexpectedly, nucleophilic substitution of benzyloxy by methoxy group was observed.
Concise and efficient synthesis of calothrixin B
Sissouma, Drissa,Maingot, Lucie,Collet, Sylvain,Guingant, Andre
, p. 8384 - 8389 (2007/10/03)
A convergent synthesis of the naturally occurring alkaloid Calothrixin B is presented, which used a regioselective hetero-Diels-Alder reaction between a "push-pull" 2-aza-diene and a N-protected 3-bromo-9H-carbazole-1,4- dione to construct the five-ring skeleton of the molecule. Protection of the indole motif with a benzyl group was unattractive for delivery of sufficient target material because the removal of the protecting group had not been high yielding. We therefore elected to temporarily protect the indole motif with a more labile benzyloxycarbonyl group. Accordingly, the synthesis of calothrixin B proceeded in 17% overall yield over 9 steps from the commercially available 1,2,3,9-tetrahydro-4H-carbazol-4-one.
A synthesis of calothrixin B
Sissouma, Drissa,Collet, Sylvain C.,Guingant, André Y.
, p. 2612 - 2614 (2007/10/03)
A new short and efficient synthesis of calothrixin B is reported. The key reaction is a hetero-Diels-Alder reaction between 3-bromo-9H-carbazole-1,4-dione and a 'push-pull' 2-aza-1,3-diene.
