Discovery of sugarnitriles A and B, and structural reassignment of SF-2140, from a sugarcane endophytic actinomycete Amycolatopsis sp. JS-O27

• Qiuyun Li,
• Ying Liu,
• Baoyue Wei,
• Yu Sun,
• Di Mao,
• Yanmin Zou and
• Shan Lu

Beilstein J. Org. Chem. 2026, 22, 1114–1121, doi:10.3762/bjoc.22.90

• Qiuyun Li Ying Liu Baoyue Wei Yu Sun Di Mao Yanmin Zou Shan Lu School of Pharmacy, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China 10.3762/bjoc.22.90 Abstract Three rare cyano-substituted indole N-glycosides, SF-2140 (1) and its two previously undescribed derivatives, sugarnitriles A

• constants and NOESY data, and comparison of their electronic circular dichroism (ECD) spectra. Compounds 1 and 3 exhibited moderate to weak antibacterial activity against Escherichia coli at 100 μg/mL. Keywords: Amycolatopsis sp.; indole N-glycosides; SF-2140; structure reassignment; sugarnitriles

• promising source for discovering new bioactive natural products. Indole alkaloids stand out for their structural diversity and broad pharmacological properties, including anti-inflammatory [11][12], anticancer [13][14], and anti-HIV [15][16] effects. Among indole alkaloids, indole N-glycosides represent a

Recent advances in copper-catalyzed direct hydroamination of alkenes with (hetero)aromatic amines

• Hyejeong Lee and
• Yunmi Lee

Beilstein J. Org. Chem. 2026, 22, 925–947, doi:10.3762/bjoc.22.73

• significantly affecting the reaction efficiency. In addition to simple anilines, diverse heteroaromatic amines including indole, pyrrole, triazole, carbazole, and imidazole derivatives participated effectively in the copper-catalyzed conjugate addition, providing the corresponding β-amino products 3 in high

• addition of 2-arylethynylaniline 29 to form β-amino ketone intermediate II, which existed in equilibrium with its enol form. Subsequent coordination of the alkyne to the copper center promoted intramolecular 5-endo-dig hydroamination, yielding indole product 32 after proton transfer. Overall, the copper

Synthesis of heterocycles based on azomethine ylides from α-amino acids (or amines) and carbonyl compounds

• Ekaterina V. Berezhnaya,
• Alexander I. Ponyaev,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2026, 22, 705–741, doi:10.3762/bjoc.22.55

• of regio- and endo-stereoselective spiro- and dispiro-derivatives of azabicyclo[3.2.0]heptane 151 and 152 is due to orbital control along with second orbital interactions [101]. In 2015, Wu and co-workers described a multicomponent synthesis of various spiro[indole-pyrrolizine], spiro[indole

• -indolizine], and spiro[indole-pyrrolidine] gem-bisphosphonates 154 via reactions between substituted isatins 140, tetraethylvinylidenebis(phosphonate) 153, and amino acids 100 in the presence of montmorillonite (Scheme 51) [102]. Although this reaction proceeds moderately without a catalyst, the introduction

• isatins and amino acids, in which the nucleophilic center is activated due to the possibility of delocalization of the negative charge involving the indole ring. In these reactions, the authors used ʟ-proline, piperidine-2-carboxylic acid, and sarcosine. In all cases, the synthesis proceeds with high

Recent advances in the stereoselective synthesis of distal biaxially chiral molecules

• Fanxing Zhou,
• Chen Zhang,
• Lingyu Sun,
• Yiyun Fang,
• Siming Zheng,
• Lina Hu,
• Mengyang Shen,
• Zhen Zhao,
• Wei Xu,
• Yunqiang Sun and
• Zi-Qiang Rong

Beilstein J. Org. Chem. 2026, 22, 461–479, doi:10.3762/bjoc.22.34

• assembly of complex distal biaxial architectures that are difficult to access via direct or stepwise axis formation alone. In 2019, Bertuzzi and co-workers achieved the first enantioselective synthesis of an axially chiral indole–quinoline system (Scheme 25) [64]. They employed a central-to-axial oxidative

• chiral polysubstituted naphthalene scaffolds. Enantioselective Ni-catalyzed Suzuki–Miyaura cross-coupling reaction. The stereoselective synthesis of axial chiral indole–quinoline systems. The synthesis of bisbenzofuran atropisomeric oligoarenes containing two distal C–C stereogenic axes. Funding This

Recent advances in the cleavage of non-activated amides

• Eun-Sol Choi and
• Hyo-Jun Lee

Beilstein J. Org. Chem. 2026, 22, 352–369, doi:10.3762/bjoc.22.23

• reacted smoothly with p-methoxyphenyl (PMP) amine, p-methoxybenzyl (PMB) amine, N-benzyl-N-methylamine, and indole, generating the corresponding amides 99–102 in good to excellent yields. Based on kinetic studies, the authors proposed a plausible mechanism in which the dihydrogen tetrametaphosphate

Ring contraction and ring expansion reactions in terpenoid biosynthesis and their application to total synthesis

• Nicolas Kratena,
• Nicolas Heinzig and
• Peter Gärtner

Beilstein J. Org. Chem. 2026, 22, 289–343, doi:10.3762/bjoc.22.21

• addition towards the highly electrophilic α-diketone moiety. With this, the bicyclic lathyrane skeleton of jolkinol C (45) is assembled selectively from casbene. The large family of indole meroterpenoids [94][95][96][97][98] also contains an interesting, enzyme-mediated ring-expansion reaction. According

• to the detailed research of their biosynthesis carried out by Oikawa et al. [99][100] the terpenoid penitrem A (46) is formed from PC-M4 (47, see Scheme 16A). This precursor, exhibiting a 5-membered ring annulated onto the indole core, reacts in a HAT reaction under mediation of PtmK, an enzyme

• ) directly. From here another oxy-cyclisation and aromatic chlorination leads to the most complex member of the indole meroterpenoids, penitrem A (46). Another example of a ring expansion reaction, in this case of the aromatic 5-membered ring of an indole, was discovered to be operational in the biosynthetic

Total synthesis of natural products based on hydrogenation of aromatic rings

• Haoxiang Wu and
• Xiangbing Qi

Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4

• catalysts, they synthesized 2-substituted quinoxalines 52 in high yield. For benzofuran, indole and other heteroarenes, hydrogenation of these easily accessible building blocks is rare. In 2020, Ding and co-workers demonstrated the selective reduction of benzoannelated five-membered heteroaromatic compounds

• process relies on the rapid interconversion of the enantiomers in the racemic substrate, which in turn relies on the acid-promoted isomerization between the aromatic indole and the nonaromatic exocyclic enamine intermediate. Very recently, Chen and co-workers reported that using a Mn catalyst with

• % yield over two steps [76]. Alkylation with MeI furnished pyridinium 91, which was hydrogenated in two steps with NaBH3CN to the fully saturated piperidine 92. Acidic removal of the benzoyl group triggered auto-oxidation to the indole, and subsequent hydrolysis of methyl ester delivered the target

Advances in Zr-mediated radical transformations and applications to total synthesis

• Hiroshige Ogawa and
• Hugh Nakamura

Beilstein J. Org. Chem. 2026, 22, 71–87, doi:10.3762/bjoc.22.3

• desired bibenzyl dimer 44. The reaction proceeded efficiently regardless of the electronic character of the aromatic ring (Scheme 8B, 44a–c). Furthermore, substrates containing various heteroaromatic motifs such as thiophene (44d), indole (44e), and oxazole (44f) also underwent smooth dimerization. The

Total synthesis of asperdinones B, C, D, E and terezine D

• Ravi Devarajappa and
• Stephen Hanessian

Beilstein J. Org. Chem. 2025, 21, 2730–2738, doi:10.3762/bjoc.21.210

• members of prenylated indole alkaloids exhibiting α-glucosidase activity is described. Asperdinones B, C, D, and E are characterized by the presence of a (3R)-3-indolylmethylbenzodiazepine-2,5-dione unit at C-3 of C4–C7 prenylated indoles. Methods of direct and indirect prenylation of indole and

• tryptophan were explored. Different approaches were adopted for the functionalization of C4–C7 prenylindoles at C-3 using Negishi cross-coupling methods. The asperdinones are among the rare tryptophan-derived indole alkaloids which appear to have undergone epimerization due to genetic alteration of specific

• gene clusters that code for a (3R) configuration. Keywords: C–H activation; indole alkaloid; Negishi reaction; prenylation; Introduction Alkaloids constitute an important family of naturally occurring compounds with a rich history in the annals of bioactive compounds [1]. Among these, the family of

Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• heterocyclic aldehydes such as furfural (3v), thiophene (3w) and indole (3x) carboxaldehydes. Application of the optimized EDA-catalyzed Knoevenagel conditions to thiazolidine-2,4-dione (2b) afforded the expected product 4a in moderate yield (Supporting Information File 1, Table S1). Adding excess thiazolidine

Palladium-catalyzed regioselective C1-selective nitration of carbazoles

• Vikash Kumar,
• Jyothis Dharaniyedath,
• Aiswarya T P,
• Sk Ariyan,
• Chitrothu Venkatesh and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2025, 21, 2479–2488, doi:10.3762/bjoc.21.190

• 2s (36%) and 2s' (15%). It is worth noting that under the standard reaction conditions, indole substrates 1t and 1u failed to afford the desired products 2t and 2u. Encouraged by these results, and to further demonstrate the synthetic utility of the established reaction protocol, we carried out a

Synthesis of the tetracyclic skeleton of Aspidosperma alkaloids via PET-initiated cationic radical-derived interrupted [2 + 2]/retro-Mannich reaction

• Ru-Dong Liu,
• Jian-Yu Long,
• Zhi-Lin Song,
• Zhen Yang and
• Zhong-Chao Zhang

Beilstein J. Org. Chem. 2025, 21, 2470–2478, doi:10.3762/bjoc.21.189

• intense substrate decomposition (Table 1, entries 6–8). These results showed that MeCN is the best solvent for the reaction. Finally, we investigated the effects of an alternative N-substituent in the indole moiety, and the reaction time and temperature on the photocyclization results. Boc-substituted

• 62% and 58%, respectively. Computational study The synthesis of (±)-aspidospermidine (1) and (±)-limaspermidine (2) showcased the effectiveness of our strategy for constructing complex monoterpene indole alkaloids [26]. In this work, we turned our attention to investigating the mechanistic

• the formation of benzyl radical IN2, which has a boat-like seven-membered ring. This structural feature may facilitate formation of the C19–C12 bond, even in the presence of critical steric hindrance between the C5 quaternary carbon and the indole moiety. Further DFT investigation proved challenging

Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds

• Natalya Akhmetdinova,
• Ilgiz Biktagirov and
• Liliya Kh. Faizullina

Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185

• [96] used the semipinacol rearrangement as a key step in converting indole 219 to spirooxindole 221. The spirooxindole alkaloids, (−)-citrinadin A and (+)-citrinidin B, exhibit notable activity against murine leukemia L1210 (217, IC50 6.2 μg/mL; 229, 10 μg/mL) and human epidermoid KB cells (218, IC50

• 10 μg/mL). Sequential interaction of indole 219 with pyridinium p-toluenesulfonate (PPTS) and excess of Davis’ oxaziridine 222, an effective oxidizing agent for synthesis of spirooxindole alkaloids, led to epoxide 220. Labile oxirane 220, without isolation, was subjected to a semipinacol

An Fe(II)-catalyzed synthesis of spiro[indoline-3,2'-pyrrolidine] derivatives

• Elizaveta V. Gradova,
• Nikita A. Ozhegov,
• Roman O. Shcherbakov,
• Alexander G. Tkachenko,
• Larisa Y. Nesterova,
• Elena Y. Mendogralo and
• Maxim G. Uchuskin

Beilstein J. Org. Chem. 2025, 21, 2383–2388, doi:10.3762/bjoc.21.183

• -unsaturated ketone; dearomatization; indole; spirocyclization; spiro[indoline-3,2'-pyrrolidine]; Introduction Spiro[indoline-3,2'-pyrrolidine] derivatives represent an important class of organic compounds found in both natural products (e.g., coerulescine [1], horsfiline [2], and elacomine [3]) and synthetic

• . Third, the introduction of an ortho-methyl substituent on the ketone moiety (3m) likewise suppressed product formation, likely due to steric hindrance interfering with cyclization at the C3 position of the indole ring. Based on literature precedents [15][16], we propose a mechanism involving a radical

Pathway economy in cyclization of 1,n-enynes

• Hezhen Han,
• Wenjie Mao,
• Bin Lin,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173

• , the Liu group developed a gold-catalyzed tandem cycloisomerization, offering controllable synthesis of either indolo[2,3-a]quinolizine or indolizino[8,7-b]indole derivatives (Scheme 10) [17]. When the indole nitrogen of the substrate was substituted with electron-donating groups (EDGs) and the alkyne

• of propiolamide was equipped with a bulky substituent, the 6-exo-dig cyclization was initially triggered under gold(I)-catalysis, leading to intermediate 43. Then the indolizino[8,7-b]indole skeleton 44 ultimately was constructed via a tandem 5-exo-dig cyclization (Scheme 10, path a). When the indole

• controllable cyclization of tryptamine-derived ynamides to synthesize two types of indole alkaloid skeletons (Scheme 13) [20]. For alkyl-substituted alkynes, the ynamide activated by BiCl3 was attacked by indole's C3-position to form spirocyclic intermediate 58. Subsequent 1,2-migration then exclusively

Thiadiazino-indole, thiadiazino-carbazole and benzothiadiazino-carbazole dioxides: synthesis, physicochemical and early ADME characterization of representatives of new tri-, tetra- and pentacyclic ring systems and their intermediates

• Gyöngyvér Pusztai,
• László Poszávácz,
• Anna Vincze,
• András Marton,
• Ahmed Qasim Abdulhussein,
• Judit Halász,
• András Dancsó,
• Gyula Simig,
• György Tibor Balogh and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2220–2233, doi:10.3762/bjoc.21.169

• -dioxides, we aimed at elaborating a synthetic procedure for the preparation of their pyrrole-fused counterparts, 2,9-dihydro[1,2,3]thiadiazino[5,6-g]indole 1,1-dioxide derivatives. The simple and versatile process led, via Fischer indole cyclization of the corresponding hydrazones, to a wide structural

• metabolic stability of the most promising derivatives was also determined using human liver microsomes. Keywords: early ADME characterization; Fischer indole cyclization; heterocycles; indoles; lead-likeness; new ring systems; physicochemical characterization; Introduction Considering the published

• -dioxides and their 3,4-dihydro derivatives 2 (R3 = Me) were found to have remarkable in vivo anxiolytic activity [12], we aimed to prepare further congeners exhibiting a higher potency in this field. It is well known that synthetic as well as naturally occurring compounds containing an indole moiety

Electrochemical cyclization of alkynes to construct five-membered nitrogen-heterocyclic rings

• Lifen Peng,
• Ting Wang,
• Zhiwen Yuan,
• Bin Li,
• Zilong Tang,
• Xirong Liu,
• Hui Li,
• Guofang Jiang,
• Chunling Zeng,
• Henry N. C. Wong and
• Xiao-Shui Peng

Beilstein J. Org. Chem. 2025, 21, 2173–2201, doi:10.3762/bjoc.21.166

• characteristics. Electrochemical construction of five-membered rings from alkynes attracted increasing attention due to the notable advantages of electrochemical transformations and facile access of alkynes. Indole skeletons were constructed successfully through electrochemical intramolecular coupling of ethynyl

• ][126][127][128][129][130][131][132][133][134][135][136]. Recently, Shi has disclosed the synthesis or transformation of indoles and developed indole-derived platform molecules [137][138][139][140][141][142][143][144][145][146][147][148][149][150][151][152][153][154][155][156][157][158][159][160][161

• the indole frame (Scheme 2) [185]. In the presence of KPF6 and NaOAc, subjection of alkyne 3 and aniline 4 to [RuCl2(p-cyneme)]2-catalyzed electrochemical annulation formed the titled indole 5 successfully. After studying the reaction in details, the best reaction conditions were acquired as following

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

• evolves towards cyclic acetals (Scheme 4) [32]. Exploring methods for the conversion of glycolaldehyde (GCA) to 3-(indol-3-yl)-2,3-dihydrofurans in organic solvents, Gu et al. reported a three-component reaction combining GCA, ethyl acetoacetate as 1,3-dicarbonyl component and indole. Using glycolaldehyde

• oxygen in alcoholic medium has also been reported (Scheme 37) [121][122]. Riguet synthesized γ-lactams through a Ugi 4-center 3-component reaction (U-4C-3CR) protocol. HFO was used as the electrophile in the Friedel–Crafts (FC) alkylation reactions of indole catalyzed by diphenylprolinol silyl ether. The

The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products

• Dong-Xing Tan and
• Fu-She Han

Beilstein J. Org. Chem. 2025, 21, 2085–2102, doi:10.3762/bjoc.21.164

• (−)-aspidospermidine (−)-Hunterine A (14) and (−)-aspidospermidine (15) are monoterpene indole alkaloids, which were isolated from Hunteria zeylanica and Apocynaceae plants, respectively [56][57]. Structurally, these two natural products both contain the fused polycyclic skeleton core bearing four consecutive

Discovery of cytotoxic indolo[1,2-c]quinazoline derivatives through scaffold-based design

• Daniil V. Khabarov,
• Valeria A. Litvinova,
• Lyubov G. Dezhenkova,
• Dmitry N. Kaluzhny,
• Alexander S. Tikhomirov and
• Andrey E. Shchekotikhin

Beilstein J. Org. Chem. 2025, 21, 2062–2071, doi:10.3762/bjoc.21.161

• heterocyclic scaffolds are widely used in the treatment of various diseases, making them a common focus of research [1]. A substantial part of these compounds incorporate five- or six-membered nitrogen heterocycles. The indole and quinazoline cores represent two pharmacologically significant heterocyclic

• systems, exhibiting a wide range of biological activity, high level of druglikeness and broad opportunities for derivatizations, that make them privileged scaffolds in drug discovery [2][3]. The pharmaceutical significance of indole and quinazoline rings is evident by numerous FDA-approved drugs across

• structural fusion of indole and quinazoline pharmacophores offers exceptional opportunities for designing new therapeutic agents, combining the proven bioactivities of both privileged scaffolds. Chemical ways for the synthesis of indolo[1,2-c]quinazolines (Figure 1, top) are numerous and cover different

Bioinspired total syntheses of natural products: a personal adventure

• Zhengyi Qin,
• Yuting Yang,
• Nuran Yan,
• Xinyu Liang,
• Zhiyu Zhang,
• Yaxuan Duan,
• Huilin Li and
• Xuegong She

Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160

• , bioinspired total synthesis of three types of natural products, namely diterpenoids (chabranol, and monocerin), alkaloids (indole, hydroquinoline, and monoterpenoid−indolidinoid hybrid), and gymnothelignans are discussed. Based on these achievements on bioinspired total synthesis, we provide some information

• with an acid and base-promoted saponification inversed the C12 alcohol stereochemistry, which ultimately provided (12R)-hydroxymonocerin. Total synthesis and bioinspired skeletal diversification of (12-MeO)-tabertinggine In 2013, Kam and co-workers reported the discovery of two novel indole alkaloids

• skeletons are of great interests to synthetic chemists, since the biological studies are limited due to material scarcity in the nature. Structurally, tabertinggine contains an aza-[3.2.1] bridged skeleton linked to indole C2 position. To rationalize how this unique structure is generated in nature (Scheme

Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis

• Lihua Wei,
• Rui Yang,
• Zhifeng Shi and
• Zhiqiang Ma

Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151

• ]. Snyder and co-workers applied this method to synthesize arboridinine, an indole alkaloid isolated from a Malaysian Kopsia species (Scheme 24) [66]. The synthesis commenced with tert-butyloxycarbonyl (Boc)-protected tryptamine 181, which was converted into diol 182 in two steps. Initial attempts to forge

• indole derivatives mediated by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is an efficient strategy that the Cook group utilized in the total synthesis of several indole alkaloids [75][76][77]. In 2005, they reported the synthesis of vincamajine-related indole alkaloids, among which

Rhodium-catalysed connective synthesis of diverse reactive probes bearing S(VI) electrophilic warheads

• Scott Rice,
• Julian Chesti,
• William R. T. Mosedale,
• Megan H. Wright,
• Stephen P. Marsden,
• Terry K. Smith and
• Adam Nelson

Beilstein J. Org. Chem. 2025, 21, 1924–1931, doi:10.3762/bjoc.21.150

• estimation of the yield of each product (Figure 2, panel B). It was found that many reactions involving alcohol- (e.g., C1–5, C8, C11 and C14) and indole- (e.g., C3, C12 and C15) containing co-substrates yielded intermolecular products, whilst those involving nitrile-containing co-substrates (C9 and 10) and

• reaction modes of dirhodium carbenoids that were possible [14]. Overall, products were formed via O–H insertion into an alcohol (to give 14 products) or phenol (→ 2-4 and 3-4a); N–H insertion into an indole (→ 1-3a, 1-15b, 2-3a, 2-15b and 4-3), sulfonamide (→ 2-6), aminopyrimidine (→ 2-13 and 4-13) or

• amine (→ 4-18); cyclopropanation (→ 2-7); and formal C–H insertion into an indole (→ 1-15a and 2-15a) or naphthol (→ 2-4 and 3-4b). In the case of 4 (2-naphthol) and 15 (5-methoxyindole), co-substrates containing functional groups with more than one potentially reactive site, two regioisomeric products

Preparation of spirocyclic oxindoles by cyclisation of an oxime to a nitrone and dipolar cycloaddition

• Beth L. Ritchie,
• Alexandra Longcake and
• Iain Coldham

Beilstein J. Org. Chem. 2025, 21, 1890–1896, doi:10.3762/bjoc.21.146

• , sore throats, toothache, ulcers, and snake bites [1]. The medicinal qualities of these plants are ascribed to the presence of alkaloids, and they are rich in many different indole and oxindole alkaloids [2]. About 100 Alstonia alkaloids are known, with more being isolated on a regular basis [3][4

• ][10][11][12][13]. Of note, Cook and co-workers described an elegant approach using tryptophan as a starting material and an oxidative rearrangement of an indole that allows access to a variety of spirooxindole alkaloids from the Alstonia genus [14]. An efficient way to construct cyclic nitrogen

Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules

• Wei Liu and
• Xiaoyu Yang

Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145

• , the application of CPA catalysis in the asymmetric synthesis of other forms of molecular chirality has received less attention. While List and co-workers reported the first CPA-catalyzed asymmetric synthesis of helically chiral azahelicenes through the Fischer indole synthesis back in 2014 [12], the

• , resulting in kinetic resolution with an exceptional performance. In 2025, Zhou and co-workers disclosed the asymmetric synthesis of planarly chiral macrocycles via CPA-catalyzed atroposelective macrocyclization [42]. The authors devised and prepared a series of indole-based hydroxy-substituted carboxylic

• . Investigations of the substrate scope revealed the compatibility of the method with various substitutions on the indole moiety and modifications to the length of the ansa chain, which produced planarly chiral macrocycles with up to 99% ee. In addition, this method was successfully employed for the catalytic