The photodecarboxylative addition of carboxylates to phthalimides as a key-step in the synthesis of biologically active 3-arylmethylene-2,3-dihydro-1H-isoindolin-1-ones

• Ommid Anamimoghadam,
• Saira Mumtaz,
• Anke Nietsch,
• Gaetano Saya,
• Cherie A. Motti,
• Jun Wang,
• Peter C. Junk,
• Ashfaq Mahmood Qureshi and
• Michael Oelgemöller

Beilstein J. Org. Chem. 2017, 13, 2833–2841, doi:10.3762/bjoc.13.275

• compound 4, originating from intramolecular nucleophilic substitution, was obtained as a byproduct in 25–30%. Noteworthy, compound 4 is formed as the only product when 1a is treated with organometallic reagents [48][49][50]. When the photoreaction was repeated in a 1:1 mixture of acetone and pH 7 buffer at

• bond formation (path A), as postulated by Griesbeck et al. for the photocyclization of phthaloyl-L-methionine [58]. Alternatively, the alcoholate obtained after C–C bond formation may cyclize to the oxazolidine (path B), as known from reactions of 1a with organometallic reagents [48][49][50]. When

Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective

• Yaroslav D. Boyko,
• Valentin S. Dorokhov,
• Alexey Yu. Sukhorukov and
• Sema L. Ioffe

Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220

• intermediate 45, which was subjected to Wittig olefination. Subsequent aza-Sakurai cyclization of intermediate 46 provided tricyclic derivative 47 as a single stereoisomer, which was then transformed into target myrioneurinol by standard operations. Addition of organometallic reagents to conjugated

• relevant compounds. However, a number of challenges still remain to be addressed in this methodology, namely: (1) the extension of the scope of C-nucleophiles that can be involved in conjugate addition to nitrosoalkenes; (2) the development of general methods for coupling nitrosoalkenes with organometallic

• reagents; (3) the elaboration of tandem and domino-processes utilizing conjugate addition of C-nucleophiles to nitrosoalkenes and finally, (4) the design of catalytic enantioselective versions of the Michael addition to nitrosoalkenes (for advances in catalytic asymmetric cycloadditions of nitrosoalkenes

Effect of uridine protecting groups on the diastereoselectivity of uridine-derived aldehyde 5’-alkynylation

• Raja Ben Othman,
• Mickaël J. Fer,
• Laurent Le Corre,
• Sandrine Calvet-Vitale and
• Christine Gravier-Pelletier

Beilstein J. Org. Chem. 2017, 13, 1533–1541, doi:10.3762/bjoc.13.153

• organometallic reagents onto nucleoside aldehyde (Table 1), we decided to investigate the influence of the protecting groups of the uridine aldehyde on the stereochemical outcome of the nucleophilic addition of a Grignard reagent and we wish to report herein the results of our study. Results and Discussion We

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

• M. Fernanda N. N. Carvalho,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122

• the addition of organometallic reagents to the camphor carbonyl group allows for selective introduction of additional substituents and functional groups (e.g., as in [7]). Camphor was the source of chirality in Holton’s taxol synthesis [8] and other approaches to the taxane group of compounds [9][10

Synthesis of new pyrrolidine-based organocatalysts and study of their use in the asymmetric Michael addition of aldehydes to nitroolefins

• Alejandro Castán,
• Ramón Badorrey,
• José A. Gálvez and
• María D. Díaz-de-Villegas

Beilstein J. Org. Chem. 2017, 13, 612–619, doi:10.3762/bjoc.13.59

• tuneable catalytic motifs to be used in organocatalysis starting from the chiral pool. Highly modular chiral aminodiol derivatives were obtained by the addition of organometallic reagents to chiral imines derived from (R)-glyceraldehyde – which is easily accessible from D-mannitol – and these were

Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis

• Flavio Fanelli,
• Giovanna Parisi,
• Leonardo Degennaro and
• Renzo Luisi

Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51

• -Haloalkyllithiums are a useful class of organometallic reagents widely employed in synthetic chemistry. In fact, they allow the direct homologation of carbonyl compounds and imines leading to β-halo-alcohols and amines that are useful building blocks [29][30][31]. This work represents a remarkable example of flash

• example on the use of microreactor technology for the development of sustainable chemical processes, is represented by the direct introduction of the tert-butoxycarbonyl group into organometallic reagents [34]. The reaction between organolithium reagents and di-tert-butyl dicarbonate run under flow

The reductive decyanation reaction: an overview and recent developments

• Jean-Marc R. Mattalia

Beilstein J. Org. Chem. 2017, 13, 267–284, doi:10.3762/bjoc.13.30

• organometallic reagents or other nucleophiles [139]. Nambo et al described the preparation of triarylacetonitriles using sequential Pd-catalyzed arylations. Triarylacetonitriles obtained can be transformed into various species including triarylmethanes by treatment with MeMgCl (Scheme 30) [140]. In this case a

Efficient access to β-vinylporphyrin derivatives via palladium cross coupling of β-bromoporphyrins with N-tosylhydrazones

• Vinicius R. Campos,
• Ana T. P. C. Gomes,
• Anna C. Cunha,
• Maria da Graça P. M. S. Neves,
• Vitor F. Ferreira and
• José A. S. Cavaleiro

Beilstein J. Org. Chem. 2017, 13, 195–202, doi:10.3762/bjoc.13.22

• features – stoichiometric organometallic reagents are not required for the coupling reaction and di- and trisubstituted olefins can be prepared with high stereoselectivity. In fact, N-tosylhydrazones used in this methodology can be easily prepared from carbonyl compounds (Scheme 1), as it has been well

• demonstrated by Barluenga and co-workers [11][26][27]. This methodology allowed the development of novel protocols enabling transformations that are difficult to achieve with other reactions and include other important features as: stoichiometric organometallic reagents are not required for the coupling

Synthesis of polyhydroxylated decalins via two consecutive one-pot reactions: 1,4-addition/aldol reaction followed by RCM/syn-dihydroxylation

• Michał Malik and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2016, 12, 2602–2608, doi:10.3762/bjoc.12.255

• of this transformation, three new stereogenic centers are generated. A copper-catalyzed 1,4-addition of organometallic reagents to cyclic α,β-unsaturated ketones, followed by an aldol reaction has been already used in the synthesis of complex natural products [26][27][28][29][30][31][32][33

Conjugate addition–enantioselective protonation reactions

• James P. Phelan and
• Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

• has been the use of rhodium(I) transition metal catalysts and axially chiral phosphorous ligands (Figure 2). Additionally, because organometallic reagents are often utilized as nucleophiles, an exogenous proton source, which can impact the transformation’s enantioselectivity, is frequently needed. In

• co-workers demonstrated that chiral lanthanum and samarium tris(BINOL) complexes (Figure 3), developed by the Shibasaki group for asymmetric Michael additions using malonates and organometallic reagents, are effective catalysts for the sequential conjugate addition of 4-tert-butyl(thiophenol) to α,β

Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

• Sebastian Bretzke,
• Stephan Scheeff,
• Felicitas Vollmeyer,
• Friederike Eberhagen,
• Frank Rominger and
• Dirk Menche

Beilstein J. Org. Chem. 2016, 12, 1111–1121, doi:10.3762/bjoc.12.107

• the chiral amine core of these alkaloids. For the synthesis of the nitrogen appending the quaternary center we tested a method developed by the Ellman group [46][47], which relies on an asymmetric addition of organometallic reagents to enantiopure tert-butanesulfinyl ketimines of type 29 and 30

Carbon–carbon bond cleavage for Cu-mediated aromatic trifluoromethylations and pentafluoroethylations

• Tsuyuka Sugiishi,
• Hideki Amii,
• Kohsuke Aikawa and
• Koichi Mikami

Beilstein J. Org. Chem. 2015, 11, 2661–2670, doi:10.3762/bjoc.11.286

• perfluoroalkyl organometallic reagents (CnF2n+1M) with high reactivity, act as prominent cross-coupling participants in aromatic perfluoroalkylation reactions [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. In order to prepare CnF2n+1Cu species, several

Copper-catalyzed stereoselective conjugate addition of alkylboranes to alkynoates

• Takamichi Wakamatsu,
• Kazunori Nagao,
• Hirohisa Ohmiya and
• Masaya Sawamura

Beilstein J. Org. Chem. 2015, 11, 2444–2450, doi:10.3762/bjoc.11.265

• . Keywords: alkylborane; alkynoate; conjugate addition; copper; multisubstituted alkene; Introduction Copper-mediated conjugate additions of organometallic reagents to alkynoates are powerful tools for the synthesis of multisubstituted alkenes [1][2][3][4][5][6][7][8]. Because of their broad availability

• and their compatibility with a multitude of functional groups, organoboron compounds are especially popular organometallic reagents. Recently, Yamamoto and co-workers developed copper-catalyzed conjugate additions of aryl- and allylboron compounds to alkynoates [9][10], but alkylboron compounds have

Copper-catalyzed asymmetric conjugate addition of organometallic reagents to extended Michael acceptors

• Thibault E. Schmid,
• Sammy Drissi-Amraoui,
• Christophe Crévisy,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2015, 11, 2418–2434, doi:10.3762/bjoc.11.263

• provided dramatic breakthroughs during the last two decades. This review aims to describe the early examples and recent advances in copper-catalyzed asymmetric conjugate additions of organometallic reagents to extended Michael acceptors. First, seminal reports dealing with the reactivity of extended

Copper-catalyzed arylation of alkyl halides with arylaluminum reagents

• Bijay Shrestha and
• Ramesh Giri

Beilstein J. Org. Chem. 2015, 11, 2400–2407, doi:10.3762/bjoc.11.261

• catalyzed by Pd and Ni, exploit a wide range of organometallic reagents of Mg, Zr, Zn, Sn, Al, B, Si and In as sources of nucleophiles. Among these metals/non-metals, Al offers a unique feature due to its high chemoselectivity and Lewis acidity [10][11][12]. In addition, Al also has low toxicity and is an

• inexpensive and earth-abundant metal. Organoaluminum reagents can be prepared directly from metallic aluminum [13][14][15], which further highlights the potential scope of these reagents in organic synthesis. However, despite extensive investigations and applications of organometallic reagents of Si, B, Mg

• conditions, a catalyst derived from the combination of CuI and 2-(diphenylphosphino)-N,N-dimethylaniline (PN-1) remains highly effective for coupling many of these organometallic reagents with aryl halides. In order to expand the scope of our coupling reactions, we utilized the standard condtions for the

Development of variously functionalized nitrile oxides

• Haruyasu Asahara,
• Keita Arikiyo and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2015, 11, 1241–1245, doi:10.3762/bjoc.11.138

• -methylamide) is widely used for the conversion of less reactive amide moieties into other carbonyl functionalities [8][9]. The two oxygen atoms of the methoxy and carbonyl groups coordinate to the organometallic reagents, thereby suppressing further reaction with the obtained aldehyde or ketone. However, this

• activation of the carbamoyl group and for preventing over-addition by organometallic reagents. Isoxazole-3-carboxamide 3 was successfully converted in a similar fashion. Thus, as shown in Figure 1, nitrile oxide 2 serves as an equivalent of functionalized nitrile oxides 4, thereby improving the synthetic

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• incorporated analysis technique. As the safe use of organometallic reagents has emerged as a key facet of flow chemical synthesis [58], the ITC reported on the design and implementation of a dual injection loop system that could deliver solutions of organometallic reagents (i.e., LiHMDS or n-BuLi) as a pseudo

• consistent reagent delivery is crucial. In order to address these issues flow equipment utilising adapted peristaltic pumps have been developed and applied to several mesoscale syntheses utilising common organometallic reagents (i.e., n-BuLi, Grignard reagents, DIBAL-H) [106]. The pump design uses specific

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

• Katherine M. Byrd

Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60

• copper in CA reactions will preferentially form the 1,4-addition product [1]. Since then, copper has been the most commonly used metal in DCA and ECA reactions. In terms of the nucleophiles that are used, mainly alkyl organometallic reagents derived from zinc, aluminium, lithium and magnesium are used [1

• ][3][4]. Alkenyl, alkynyl and aryl organometallic reagents have been used less frequently [78][79][80][81][82][83][84]. Feringa and co-workers reported the first copper-catalyzed ECA reactions of α,β-unsaturated lactams in 2004 [22]. They were able to perform these reactions in high yields and

• . (Note: In contrast, there have not been any rhodium-catalyzed CA reactions of alkyl nucleophiles.) Finally, (3) no 1,2-addition is observed in the rhodium variant because the organometallic reagents that are used are less reactive than the organolithium and -magnesium reagents used in the copper

Synthesis of rigid p-terphenyl-linked carbohydrate mimetics

• Maja Kandziora and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 1749–1758, doi:10.3762/bjoc.10.182

• to heat, air and moisture compared to other organometallic reagents [21]. Up to now there are not many examples of nanorod-like carbohydrate dimers with aryl-linked divalent glycosides. A mannopyranoside dimer was generated by a palladium-catalyzed Ullmann-type reductive homocoupling [22] and

An economical and safe procedure to synthesize 2-hydroxy-4-pentynoic acid: A precursor towards ‘clickable’ biodegradable polylactide

• Quanxuan Zhang,
• Hong Ren and
• Gregory L. Baker

Beilstein J. Org. Chem. 2014, 10, 1365–1371, doi:10.3762/bjoc.10.139

• feasible probably due to the interruption of the ethynyl proton in the presence of organometallic reagents [29]. As discussed above, there are two important factors that should be taken into account in order to achieve a safe and economical route resulting in precursor 1: 1) a non-explosive and cheap

Preparation of phosphines through C–P bond formation

• Iris Wauters,
• Wouter Debrouwer and
• Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

• , phosphonates, phosphinates and phosphate derivatives, etc.) are out of the scope of this review. Review Preparation of alkylphosphines via formation of a C(sp3)–P bond Reaction of organometallic reagents with halophosphines One of the main approaches to synthesize a carbon–phosphorus bond involves the

• ]. Reaction of organometallic reagents with halophosphines The reaction of an organometallic reagent with the P-atom of halophosphines is a classical method used for the synthesis of both alkenyl- and arylphosphines. The organometallic reagents are mostly Grignard reagents [136][137][138] or organolithium

• [139][140][141][142] derivatives. Other organometallic reagents such as aluminum [143] or organomercury [26][144] reagents have been used less frequently. Grignard or organolithium compounds are highly reactive nucleophiles and do not tolerate the presence of various functional groups. As a consequence

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

Synthesis of novel derivatives of 5-hydroxymethylcytosine and 5-formylcytosine as tools for epigenetics

• Anna Chentsova,
• Era Kapourani and
• Athanassios Giannis

Beilstein J. Org. Chem. 2014, 10, 7–11, doi:10.3762/bjoc.10.2

• )acetylide, THF, −50 °C, lithium phenylacetylide, THF, −78 °C → −50 °C, vinylmagnesium bromide, THF, 0 °C) afforded 3,6-dihydrodeoxycytidine derivatives 8a–e as mixtures of diastereomers. In case of 8b the diastereomers were separated by HPLC. Products arising from addition of the organometallic reagents to

• the aldehyde group (1,2-addition) were not observed. The formation of compounds 8a–d can be explained assuming a Michael-type reaction of aldehyde 5 with organometallic reagents, subsequent isomerisation of the double bond followed by removal of one TCBoc group during the reaction and work-up as shown

• in Scheme 4. Finally, cleavage of the TCBoc group was achieved by the action of the 10% Cd–Pb couple [32] on compounds 8a–d in THF and 1.0 M aq NH4OAc to provide derivatives 9a–d (Scheme 3). Conclusion In summary, the reaction of 5fC derivatives 1, 4, and 5 with organometallic reagents (RMgBr, RLi

Continuous-flow Heck synthesis of 4-methoxybiphenyl and methyl 4-methoxycinnamate in supercritical carbon dioxide expanded solvent solutions

• Phei Li Lau,
• Ray W. K. Allen and
• Peter Styring

Beilstein J. Org. Chem. 2013, 9, 2886–2897, doi:10.3762/bjoc.9.325

• ; flow chemistry; Heck; palladium; supercritical carbon dioxide; Introduction The use of cross-coupling reactions between organometallic reagents and organic halides as a straightforward method of carbon–carbon bond formation has gained much popularity over the past three decades. The development of

Garner’s aldehyde as a versatile intermediate in the synthesis of enantiopure natural products

• Mikko Passiniemi and
• Ari M.P. Koskinen

Beilstein J. Org. Chem. 2013, 9, 2641–2659, doi:10.3762/bjoc.9.300

• chiral intermediate will be discussed. Addition of organometallic reagents to Garner’s aldehyde The addition of a nucleophile to Garner’s aldehyde provides a facile access to 2-amino-1,3-dihydroxypropyl substructures. Through the addition of a carbon nucleophile also a new stereocenter is formed

• by Herold and Garner, much attention has been paid on the factors influencing the stereoselectivity. Coleman and Carpenter studied the nucleophilic addition of vinyl organometallic reagents to (S)-1 (Scheme 10) [61]. They noticed that the addition of vinyllithium in THF provided the anti-adduct 20 in