Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

• Senze Qiao,
• Zhongyu Cheng and
• Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

• macrolactones. Using engineered variants of S. venezuelae ATCC 15439 designated strains DHS200141 [71] and YJ11242 [72], 24 and 25 were transformed to the corresponding macrolides through whole cell biotransformation to append ᴅ-desosamine and perform C–H oxidation(s) by the PikC monooxygenase (Scheme 6b). In

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• resembling that of hawthorn or a harsh orange-blossom type“. Acetophenone appears in vintage Geoffrey Beene: Grey Flannel at 0.14%, and Shiseido: Zen and Gap: Om at approx. 0.014%. In 2013, Roberge, Kappe, and co-workers investigated the C–H oxidation of ethylbenzene (37) to acetophenone with oxygen as an

• somewhat similar to coumarin is phthalide (50), having a sweet and powdery scent reminiscent of coconut and tonka bean [43]. Phthalide can be considered as a top note type of coumarin. Recently, Noël and co-workers developed a method for the photochemical, decatungstate-catalyzed C–H oxidation of activated

• scale [45]. Additionally, Noël and co-workers prepared (+)-sclareolide (3a,6,6,9a-tetramethyl-1,4,5,5a,7,8,9,9b-octahydronaphtho[8,7-d]furan-2-one), a rarely used aromatic odorant reminiscent of cedar and tobacco, by C–H oxidation of (−)-ambroxan (1,5,5,9-tetramethyl-13-oxatricyclo[8.3.0.0(4,9

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• target lactone in 61% yield over two steps. The final steps involved a one-pot ozonolysis with quenching under Pinnick oxidation conditions to afford the carboxylic acid derivative in 83% yield, followed by White’s selective C–H oxidation (Scheme 26B). White’s selective C–H oxidation was also applied in

Selective benzylic C–H monooxygenation mediated by iodine oxides

• Kelsey B. LaMartina,
• Haley K. Kuck,
• Linda S. Oglesbee,
• Asma Al-Odaini and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2019, 15, 602–609, doi:10.3762/bjoc.15.55

• hypervalent iodine oxidants to mediate benzylic C–H oxidation is one area experiencing a surge of interest [22][23][24][25][26][27][28][29][30][31][32][33]. Nonmetal-based benzylic oxidations have also been mediated by species including, but not limited to, electron deficient quinones, photoexcited organic

Hypervalent iodine(III)-mediated decarboxylative acetoxylation at tertiary and benzylic carbon centers

• Kensuke Kiyokawa,
• Daichi Okumatsu and
• Satoshi Minakata

Beilstein J. Org. Chem. 2018, 14, 1046–1050, doi:10.3762/bjoc.14.92

• benzylic C–H oxidation were observed in this reaction system. Hydrolysis of the acetates 2c and 2m under basic conditions furnished the corresponding alcohols 3c and 3m, respectively, in nearly quantitative yields (Scheme 3). These results demonstrate that the present decarboxylative acetoxylation

Opportunities and challenges for direct C–H functionalization of piperazines

• Zhishi Ye,
• Kristen E. Gettys and
• Mingji Dai

Beilstein J. Org. Chem. 2016, 12, 702–715, doi:10.3762/bjoc.12.70

• enantioselective versions of these transformations. Copper-catalyzed C–H oxidation In an effort to establish a chemical toolkit to rapidly deliver oxidized drug metabolites, Touré, Sames and co-workers have discovered that piperazines could be oxidized to diketopiperazines as well as ring fragmented products under

• )piperazines by Murai et al. in 1997 [52]. Ta-catalyzed hydroaminoalkylation of piperazines by Schafer et al. in 2013 [55]. Photoredox catalysis for α-C–H functionalization of piperazines by MacMillan et al. in 2011 and 2014 [63][65][66]. Copper-catalyzed aerobic C–H oxidation of piperazines by Touré, Sames

Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism

• David Porter,
• Belinda M.-L. Poon and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 2549–2556, doi:10.3762/bjoc.11.275

• reaction volume of 1 mL). Under these conditions the yield of allylic amine 9 doubled relative to the more dilute 1:1 reaction, to 17%; 10 and 11 were not observed. Reaction using a chiral catalyst The chiral catalyst Fe(R,R′)-PDP (6) has been used previously to promote asymmetric C–H oxidation reactions

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• [7.2.0]undecane ring system 31 as found in xeniaphyllanes [3]. Finally, double C–H oxidation furnishes the β-hydroxy aldehyde 32 which can undergo a retro-aldol reaction with concomitant opening of the cyclobutane ring to form dialdehyde 33 as the common biogenetic precursor of xenicins, xeniolides and

AgOTf-catalyzed one-pot reactions of 2-alkynylbenzaldoximes with α,β-unsaturated carbonyl compounds

• Qiuping Ding,
• Dan Wang,
• Puying Luo,
• Meiling Liu,
• Shouzhi Pu and
• Liyun Zhou

Beilstein J. Org. Chem. 2013, 9, 1949–1956, doi:10.3762/bjoc.9.231

• -workers also reported many other highly functionalized isoquinoline derivatives by cascade reactions in good yields under mild conditions, such as 1-aminoisoquinolines [37] and 1-(isoquinolin-1-yl)ureas [38][39]. Recently, Deng and co-workers also described a new Pd-catalyzed C–H oxidation system for the

Aerobic radical multifunctionalization of alkenes using tert-butyl nitrite and water

• Daisuke Hirose and
• Tsuyoshi Taniguchi

Beilstein J. Org. Chem. 2013, 9, 1713–1717, doi:10.3762/bjoc.9.196

• γ-lactols, whereas the reaction in the presence of water produces 4-hydroxy-5-nitropentyl nitrate or 4-hydroxy-3-nitropentyl nitrate derivatives. Keywords: C−H oxidation; free radical; nitration; oxygen; radicals; water; Introduction Multifunctionalization reactions of simple organic molecules are

An organocatalytic route to 2-heteroarylmethylene decorated N-arylpyrroles

• Alexandre Jean,
• Jérôme Blanchet,
• Jacques Rouden,
• Jacques Maddaluno and
• Michaël De Paolis

Beilstein J. Org. Chem. 2013, 9, 1480–1486, doi:10.3762/bjoc.9.168

• regioselective oxidation of these substrates is demonstrated, extending the molecular diversity and versatility of these scaffolds. Keywords: C–H oxidation; isomerization; N-arylpyrrole; organocatalysis; Introduction Due to their presence in some natural products [1] and pharmaceuticals [2][3][4], the

• ideal for the preparation of electron donor/acceptor N-arylpyrroles as demonstrated in this study. In addition, we documented an efficient C–H oxidation of the bis(heteroaryl)methylene position promoted by CAN. Experimental General: 1H and 13C NMR spectra were recorded in deuterated chloroform on Bruker

Copper-catalyzed aerobic aliphatic C–H oxygenation with hydroperoxides

• Pei Chui Too,
• Ya Lin Tnay and
• Shunsuke Chiba

Beilstein J. Org. Chem. 2013, 9, 1217–1225, doi:10.3762/bjoc.9.138

• tertiary C–H bonds, respectively (Scheme 1b) [8][9]. Stimulated by these remote sp3 C–H oxidation reactions using the nitrogen-centered radicals derived from amidines and ketimines, we became interested to utilize oxygen-centered radicals (O-radicals) for the sp3 C–H functionalization. In this context, we

• direct 1,4-dioxygenation of alkane 10 was demonstrated by using the present method. Further studies will be carried out to develop more robust and efficient catalytic aerobic radical transformations for polyol synthesis from rather simple alkanes. Aliphatic C–H oxidation with amidines and ketimines by

• 1,5-H radical shift. Aliphatic C–H oxidation with hydroperoxides. Proposed reaction mechanisms for the formation of 2a, 3a, and 4a. Proposed reaction mechanisms for the formation of 5 and 6. The reaction of secondary hydroperoxide 1o. 1,4-Dioxygenation of alkanes. Aerobic 1,4-dioxygenation of alkanes

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48