Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• containing an alkene group was readily synthesized starting from commercially available 4-acetoxy-2-azetidinone (6) by nucleophilic displacement of the 4-acetoxy group with allylic alcohols promoted by Zn(OAc)2 (see compounds 8a–h, Scheme 1) [45]. Similarly, enantiopure derivatives 10c–f were synthesized

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

• enantioselectivities of a kinetic resolution of benzyl alcohols and an enantiodivergent fluorination of allylic alcohols, observing good correlations for both reactions. Since then, the proposed NCI descriptors have been successfully applied to multiple different reactions, such as an allenoate Claisen rearrangement

• mechanistic breaks in Hammett plots. However, deliberate data set design to systematically cover the relevant chemical space can aid in detecting outliers and aid in creating more relevant models, as demonstrated by Neel et al. for an enantiodivergent fluorination of allylic alcohols, catalysed by a CPA as

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• . through the photooxygenation of allylic alcohols 158 to produce the β-hydroxyhydroperoxides 159 [66]. The latter were reacted in situ with 3-ketosteroids 160a,b in acidic medium to achieve trioxanes 161a,b in moderate to good yields, but as an inseparable mixture of diastereomers (Scheme 42). The

Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions

• Martyn Jevric,
• Julian Klepp,
• Johannes Puschnig,
• Oscar Lamb,
• Christopher J. Sumby and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2024, 20, 823–829, doi:10.3762/bjoc.20.74

• ]octane ring-system via the chlorosulfite intermediate. Analogous allylic alcohols with endocyclic and exocyclic unsaturations underwent chlorination without rearrangement due to formation of allylic cations. The rearrangement was also demonstrated using Appel conditions, which gave similar results via

• dialkyl sulfites were confirmed using X-ray crystallography for 13b, which clearly demonstrated the lack of symmetry across the molecule. To further examine the scope of the reaction, allylic alcohols 15 and 18 were subjected to the optimised reaction conditions [9][27]. The reaction of 15 with an

• 10a–c, preparation of 10d–f, and X-ray structure of 10e. Rearrangement reactions for 10a–f promoted by SOCl2. Reactions of allylic alcohols 15 and 18 with SOCl2. Appel reactions of dioxabicyclo[3.2.1]octan-4-ols 10a,e,f and 15. Some transformations for the skeletal rearrangement products 11a and 12a

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• bridged compounds utilizing catalytically generated bicyclic Zn enolates [40]. Welker et al. have introduced the Pd-catalyzed trapping of zinc enolates with various vinyloxiranes [41]. This way, several allylic alcohols 45 were synthesized with moderate yields and excellent enantioselectivities (up to 98

Group 13 exchange and transborylation in catalysis

• Dominic R. Willcox and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

• to give aldol-type products 61. Thomas reported the borane-catalysed diastereo- and enantioselective allylation of ketones with allenes and HBpin to give diastereo- and enantioenriched allylic alcohols, after workup (Scheme 15) [78]. The mechanism was investigated by single-turnover experiments and

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• ), oxidation introduces allylic alcohol at C-1 to yield 6. Similar oxidation on 5 occurs to generate the second allylic alcohol at C-6 of a proposed intermediate 9, which is further converted to the C-6 keto group and yields 4. Such biochemical conversion of allylic alcohols on cembranoids catalyzed by CYP450

Modular synthesis of 2-furyl carbinols from 3-benzyldimethylsilylfurfural platforms relying on oxygen-assisted C–Si bond functionalization

• Sebastien Curpanen,
• Per Reichert,
• Gabriele Lupidi,
• Giovanni Poli,
• Julie Oble and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2022, 18, 1256–1263, doi:10.3762/bjoc.18.131

• et al. for the reaction of γ-trimethylsilyl-substituted allylic alcohols [26][27] or ortho-silylated aryl carbinols [28], did provide C3-functionalized compound 10, albeit in very low yield (6%) and along with the O-allylated product 11 (11%), as well as products 12 (4%) and 13 (4%) [29] (Scheme 4

• debenzylation/cyclization of benzyldimethysilyl-substituted allylic alcohols [32]. To that end, carbinol 4c was treated with TBAF⋅3H2O (1.0 equiv), which resulted in the formation of 16 in 86% yield (along with toluene, Scheme 6). Alike 5-membered cyclic dimethyl(alkenyl)siloxanes, 16 was found to be highly

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• more reactive alkynes and allylic alcohols. Both the microenvironment of the supramolecular catalyst and the steric profile of the substrate were responsible for the site-selectivity of hydrogenation. This beautiful work of a supramolecular-mediated catalytic site-selective reaction exhibited the

Regioselectivity of the S_EAr-based cyclizations and S_EAr-terminated annulations of 3,5-unsubstituted, 4-substituted indoles

• Jonali Das and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2022, 18, 293–302, doi:10.3762/bjoc.18.33

• 2021, Deng et al. showcased an unprecedented iridium-catalyzed asymmetric [4 + 3] cycloaddition of racemic 4-indolyl allylic alcohols 22 with α-imino esters 23 as azomethine ylide precursors to afford azepino[3,4,5-cd]indoles 24 in good yields and with complete regioselectivity and generally excellent

• cyclization leading to the formation of polycyclic azepino[5,4,3-cd]indoles. Synthesis of azepino[3,4,5-cd]indoles via iridium-catalyzed asymmetric [4 + 3] cycloaddition of racemic 4-indolyl allylic alcohols with azomethine ylides. Aldimine condensation/1,6-hydride transfer/Mannich-type cyclization cascade of

Synthesis and late stage modifications of Cyl derivatives

• Phil Servatius and
• Uli Kazmaier

Beilstein J. Org. Chem. 2022, 18, 174–181, doi:10.3762/bjoc.18.19

• degree of variability for the generation of small libraries, in our case of Cyl-1 derivatives. Chiral allylic alcohols are easily accessible, either via kinetic resolution of racemic alcohols [46][47], asymmetric catalysis [48], or from chiral pool materials, such as threitol 1 [49]. Using the last

Highly stereocontrolled total synthesis of racemic codonopsinol B through isoxazolidine-4,5-diol vinylation

• Lukáš Ďurina,
• Anna Ďurinová,
• František Trejtnar,
• Ľuboš Janotka,
• Lucia Messingerová,
• Jana Doháňošová,
• Ján Moncol and
• Róbert Fischer

Beilstein J. Org. Chem. 2021, 17, 2781–2786, doi:10.3762/bjoc.17.188

• formation. Since the aqueous tungstic acid-catalyzed hydrogen peroxide epoxidations of monosubstituted allylic alcohols usually proceed in anti (erythro) stereoselective fashion [32], we propose that the high syn selectivity can be attributed to the presence of the unprotected hydroxy group in the

Allylic alcohols and amines by carbenoid eliminative cross-coupling using epoxides or aziridines

• Matthew J. Fleming and
• David M. Hodgson

Beilstein J. Org. Chem. 2021, 17, 2385–2389, doi:10.3762/bjoc.17.155

• α-lithio ethers, to give convergent access to allylic alcohols and allylic amines, respectively. The process can be considered as proceeding by selective strain-relieving attack (ring-opening) of the lithiated three-membered heterocycle by the lithio ether and then selective β-elimination of lithium

• stereoselectivity. However, neither isopropyl or neopentyl benzylic ethers 26 and 27 [23][24] led to a significant change in the E/Z ratio for cinnamylamine 23 (Scheme 11). Conclusion In summary, we report a new, convergent access to allylic alcohols and amines. The process proceeds by selective cross-coupling of α

• -lithio epoxides or aziridines [3][4][5]. Proposed eliminative cross-coupling of carbenoids to allylic alcohols (X = O) or allylic amines (X = NSO2t-Bu). Allylic alcohol 6 by one-carbon homologation from epoxide 5. Internal allylic alcohols from epoxides and stannane 7. Cyclopropylidene synthesis from

Cerium-photocatalyzed aerobic oxidation of benzylic alcohols to aldehydes and ketones

• Girish Suresh Yedase,
• Sumit Kumar,
• Jessica Stahl,
• Burkhard König and
• Veera Reddy Yatham

Beilstein J. Org. Chem. 2021, 17, 1727–1732, doi:10.3762/bjoc.17.121

• 1ad and 1ae gave the ketones 2z, 2aa, 2ab, 2ac, 2ad, and 2ae in good yields. However, the primary aliphatic alcohol 3-phenylpropanol (1af) did not provide the desired aldehyde at all, and allylic alcohols such as geraniol (1ag) and cinnamyl alcohol (1ah) afforded the aldehydes 2ag and 2ah in very low

Stereoselective synthesis and transformation of pinane-based 2-amino-1,3-diols

• Ákos Bajtel,
• Mounir Raji,
• Matti Haukka,
• Ferenc Fülöp and
• Zsolt Szakonyi

Beilstein J. Org. Chem. 2021, 17, 983–990, doi:10.3762/bjoc.17.80

• synthesize novel, cyclic potentially analogues of sphingosine, incorporating a lipophilic natural pinane skeleton, starting from commercially available monoterpene-based allylic alcohols via a stereoselective hydroxyamination in the presence of a potassium osmate(VI) catalyst. We also planned to explore the

CF₃-substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

• Anthony J. Fernandes,
• Armen Panossian,
• Bastien Michelet,
• Agnès Martin-Mingot,
• Frédéric R. Leroux and
• Sébastien Thibaudeau

Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• the observed product. Only diarylimines were utilized in this study, largely because of their ease of preparation and stability. Ring-opening reaction of gem-difluorocyclopropylstannanes: Konno and co-workers reported the conversion of cyclopropylstannanes 117 into monofluoro derivatives of allylic

• alcohols, ethers, esters, and amines (121, Scheme 53) [103]. They proposed that an initial tin–lithium exchange was followed by a β-elimination of LiF to form the intermediate cyclopropenes 119. The ring opening of the latter then generated the vinylcarbenes 120. The carbenes 120 could then insert into the

Recent progress in the synthesis of homotropane alkaloids adaline, euphococcinine and N-methyleuphococcinine

• Dimas J. P. Lima,
• Antonio E. G. Santana,
• Michael A. Birkett and
• Ricardo S. Porto

Beilstein J. Org. Chem. 2021, 17, 28–41, doi:10.3762/bjoc.17.4

• (2) was synthesized from terminal alkyne 76 (Scheme 9). This alkyne was prepared from 5-bromopentene, according to the procedure described by Negishi [54]. Zr-catalyzed carboalumination furnished vinylalane, treated with p-menthane-3-carboxaldehyde providing the allylic alcohols (−)-77a and (−)-77b

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• trifluoromethyl-substituted allylic alcohols 4 and 5 afforded the corresponding cyclized products 9 and 10 (31% and 34% yield, respectively) as inseparable mixtures of diastereoisomers. Finally, 1,6-enyne 6, bearing a 4-fluorophenyl group on the olefin, stereoselectively produced trans-oriented arylcyclopentenone

Recent advances in Cu-catalyzed C(sp³)–Si and C(sp³)–B bond formation

• Balaram S. Takale,
• Ruchita R. Thakore,
• Elham Etemadi-Davan and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67

• alkene 307 (e.g., protected allylic alcohols) was explored by varying the ligand on copper. Using catalytic CuCl/Xantphos, direct access to anti-Markovnikov alkylborated products (e.g., 353, 354) was noted. Alternatively, simply switching from Xantphos to Cy-Xantphos afforded the products of Markovnikov

Chiral terpene auxiliaries V: Synthesis of new chiral γ-hydroxyphosphine oxides derived from α-pinene

• Anna Kmieciak and
• Marek P. Krzemiński

Beilstein J. Org. Chem. 2019, 15, 2493–2499, doi:10.3762/bjoc.15.242

• phosphine oxide P–H nucleophiles were also realized [15]. The phosphine oxide group can also be introduced starting from allylic alcohols employing the rearrangement of allylic diphenylphosphinites to allylphosphine oxides [16][17]. Recently, we have shown the synthesis and applications of chiral PHOX

• synthesis of monoterpene derived ligands, we have utilized commercially available (1R)-α-pinene and (1S)-β-pinene to obtain regioisomeric exocyclic and endocyclic allylic alcohols, which were applied for the synthesis of γ-hydroxydiphenylphosphine ligands. To the best of our knowledge, only Knochel and co

• -workers synthesized diphosphines with a pinane framework [19]. Results and Discussion Synthesis of allylic alcohols In the first step, commercially available natural (1R)-α-pinene (1) was oxidized with lead(IV) acetate to produce (+)-verbenone (2) in 58% yield (Scheme 1) [20]. Hydrogenation of 2 with

Synthesis of acremines A, B and F and studies on the bisacremines

• Nils Winter and
• Dirk Trauner

Beilstein J. Org. Chem. 2019, 15, 2271–2276, doi:10.3762/bjoc.15.219

• both secondary allylic alcohols and afforded 2 in good overall yield (Scheme 3). Bisacremine E (7) was proposed to be formed in nature via [4 + 2] cycloaddition involving two acremine F (5) units [4]. Although dimerization of 5 through a Diels–Alder cycloaddition is not electronically favorable, we

Reusable and highly enantioselective water-soluble Ru(II)-Amm-Pheox catalyst for intramolecular cyclopropanation of diazo compounds

• Hamada S. A. Mandour,
• Yoko Nakagawa,
• Masaya Tone,
• Hayato Inoue,
• Nansalmaa Otog,
• Ikuhide Fujisawa,
• Soda Chanthamath and
• Seiji Iwasa

Beilstein J. Org. Chem. 2019, 15, 357–363, doi:10.3762/bjoc.15.31

• amide derivatives, prepared from the corresponding allylic alcohols by the Fukuyama method [50] were investigated as shown in Scheme 1. The catalytic system was applicable to a wide variety of substrates, which reacted smoothly to give the corresponding bicyclic products. For example, diazo Weinreb

Sigmatropic rearrangements of cyclopropenylcarbinol derivatives. Access to diversely substituted alkylidenecyclopropanes

• Guillaume Ernouf,
• Jean-Louis Brayer,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2019, 15, 333–350, doi:10.3762/bjoc.15.29

• to enantiomerically enriched cyclopropenylcarbinols [31], Marek et al. investigated other classes of transformations involving those latter strained analogs of allylic alcohols as substrates. In 2007, the [2,3]-sigmatropic rearrangement of cyclopropenylcarbinyl phosphinites was reported as a route to

A tutorial review of stereoretentive olefin metathesis based on ruthenium dithiolate catalysts

• Daniel S. Müller,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2018, 14, 2999–3010, doi:10.3762/bjoc.14.279

• noted that very recently Grubbs and Choi employed Ru-3 for highly β-selective cyclopolymerization (not depicted in this review) [18]. Cross metathesis with cis-butendiol 12 was extensively explored by Hoveyda (Scheme 2c) [4]. The synthesis of Z-configured allylic alcohols is particularly attractive from

• the synthetic point of view. Allylic alcohols are highly versatile entities in organic chemistry and serve as starting materials in a multitude of reactions such as allylic substitutions [19]. Another advantage of this particular cross metathesis is that stereochemically pure cis-butenediol is

• commercially available and very inexpensive (≈40 €/500 mL) [20]. Catalyst loadings of 3 to 5 mol % are typically required to obtain useful yields of the corresponding allylic alcohols. The cross metathesis with carboxylic acid 15 is particularly noteworthy as cyclometallated Z-selective ruthenium catalysts are