Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• thus wondering if we could extend this ammonium salt-catalyzed β-selective allenoate functionalization strategy to other amino acid classes. Azlactones 1 have previously been used for γ-selective additions to allenoates under chiral phosphine catalysis [28]. In addition, glycine Schiff base derivatives

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• for the first time an enantioselective C-2 alkylation of pyridine using a chiral phosphine oxide-ligated Ni–Al bimetallic catalyst system and the protocol was found effective for a wide range of pyridines including unsubstituted pyridines, C2, C3 and C4-substituted pyridines and complex pyridines

• containing bioactive molecules (Scheme 10). To attain enantioselectivity a chiral phosphine oxide (43)-ligated Ni–Al bimetallic catalyst was used that was critical in improving the reactivity and controlling the selectivity of the reaction. Further, based on deuterium labelling experiments, KIE studies, and

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• used directly which showed comparable yields. The authors also reported preliminary results for an asymmetric variant of the reaction using (R,R)-Ph-BPE as a chiral ligand. Although the use of the chiral phosphine ligand resulted in slightly diminished yields, the authors were able to achieve ees up to

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• scaffold for a variety of natural products, bioactive compounds and pharmacological agents [79] as well as for a variety of chiral phosphine ligands [80]. As a result, the preparation of axially chiral arylpyrroles has been one of the most important areas of investigation in synthetic chemistry. In the

Visible-light-mediated copper photocatalysis for organic syntheses

• Yajing Zhang,
• Qian Wang,
• Zongsheng Yan,
• Donglai Ma and
• Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

• ] discovered the asymmetric cross-coupling of racemic tertiary alkyl halides 43 with carbazoles or indoles 44 in the CuI/chiral phosphine system. Under irradiation conditions, excitation of the copper–nucleophile complex A results in the excited state species B that engages in the electron transfer with the

All-carbon [3 + 2] cycloaddition in natural product synthesis

• Zhuo Wang and
• Junyang Liu

Beilstein J. Org. Chem. 2020, 16, 3015–3031, doi:10.3762/bjoc.16.251

• rearrangement product 99 in 85% yield. The synthesis of daphenylline (11) was completed by a seven-step synthesis from benzofuran 99. Phosphine-catalyzed enantioselective [3 + 2] annulation In 2019, Lu and co-workers disclosed a novel chiral-phosphine-catalyzed enantioselective [3 + 2] annulation of allenes and

• -workers applied the enantioselective [3 + 2] annulation to complete the formal synthesis of (−)-ditryptophenaline (12) [46] (Scheme 7C). The synthesis began with the catalytic asymmetric [3 + 2] annulation of symmetric isoindigo 104 and allene 101 with chiral phosphine catalyst 102 to give spirocyclic

• ] cycloadditions, which are usually under substrate-control. Remarkable innovation of the stereoselective palladium-catalyzed trimethylenemethane cycloaddition reported by Trost’s group, which makes use of catalytic amounts of palladium and chiral phosphine ligand 74, was applied successfully in the

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• strategy via the transfer of sp3 chirality of 27 into the bowl chirality of 28 as a key conversion (Scheme 3) [17][31]. In this context, they began with the Pd-catalyzed hydrosilylation reaction using HSiCl3 at −3 °C in the presence of a chiral phosphine ligand to furnish the hydrosilylated product which

Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions for the synthesis of chiral biaryl compounds with a large steric substituent at the 2-position

• Yongsu Li,
• Bendu Pan,
• Xuefeng He,
• Wang Xia,
• Yaqi Zhang,
• Hao Liang,
• Chitreddy V. Subba Reddy,
• Rihui Cao and
• Liqin Qiu

Beilstein J. Org. Chem. 2020, 16, 966–973, doi:10.3762/bjoc.16.85

• efficient synthesis of this scaffold [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], like Hiyama [23][24], Negishi [25][26] or Suzuki–Miyaura couplings [27][28][29][30][31][32][33][34][35][36]. In these synthetic strategies, the reaction system of palladium with chiral phosphine ligands was

• acid. A gram-scale reaction of 1h with 2a went well and provided 3h with a slightly reduced yield and ee (75% yield and 73% ee, Scheme 3), compared with 3h in Scheme 1. According to the coordination of axial chiral phosphine ligands [65][66] and our analysis, we propose a possible intermediate

Architecture and synthesis of P,N-heterocyclic phosphine ligands

• Wisdom A. Munzeiwa,
• Bernard Omondi and
• Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

• planar chiral P,N-paracyclophane phosphine ligand 132 with a relatively low yield (42%). The [2.2]paracyclophane has proved to be an important support for planar chiral phosphine ligands. The ligands are generally rigid crystalline compounds that are stable in both high and low pH media and thermally

Copper-catalyzed enantioselective conjugate addition of organometallic reagents to challenging Michael acceptors

• Delphine Pichon,
• Jennifer Morvan,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2020, 16, 212–232, doi:10.3762/bjoc.16.24

• reagents was reported by Alexakis and co-workers in 2010 [14]. After screening various chiral phosphine-based ligands, the combinations of either phosphoramidite L1 with Cu(OTf)2, or (R)-BINAP (L2) with copper thiophenecarboxylate (CuTC) appeared to be the most efficient for the addition of Et2Zn to a

Copper-catalyzed asymmetric methylation of fluoroalkylated pyruvates with dimethylzinc

• Kohsuke Aikawa,
• Kohei Yabuuchi,
• Kota Torii and
• Koichi Mikami

Beilstein J. Org. Chem. 2018, 14, 576–582, doi:10.3762/bjoc.14.44

• fluoroalkylated pyruvates is shown with dimethylzinc as a methylating reagent in the presence of a copper catalyst bearing a chiral phosphine ligand. This is the first catalytic asymmetric methylation to synthesize various α-fluoroalkylated tertiary alcohols with CF3, CF2H, CF2Br, and n-CnF2n+1 (n = 2, 3, 8

• ) groups in good-to-high yields and enantioselectivities. Axial backbones and substituents on phosphorus atoms of chiral phosphine ligands critically influence the enantioselectivity. Moreover, the methylation of simple perfluoroalkylated ketones is found to be facilitated by only chiral phosphines without

• copper. Keywords: asymmetric methylation; chiral phosphine ligand; copper catalyst; dimethylzinc; trifluoropyruvate; Introduction The introduction of fluorine atoms into organic compounds plays an important role in the discovery of lead candidates with unique biological and physicochemical properties

1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis

• Antonia Mielgo and
• Claudio Palomo

Beilstein J. Org. Chem. 2016, 12, 918–936, doi:10.3762/bjoc.12.90

• . Chiral phosphine-mediated nucleophilic catalysis has attracted considerable attention in the recent years [98][99][100][101]. However, few examples of phosphine-mediated γ-addition reactions have been reported. Pioneering studies on γ-additions of pronucleophiles to allenoates or alkynoates were first

• ] pronucleophiles to γ-substituted allenoates and/or alkynoates in the presence of a C2-symmetric chiral phosphine catalyst. Although γ-substituted allenes have been employed in many phosphine-mediated γ-additions, to date there was virtually no progress on the use of prochiral pronucleophiles in phosphine-mediated

Asymmetric α-amination of 3-substituted oxindoles using chiral bifunctional phosphine catalysts

• Qiao-Wen Jin,
• Zhuo Chai,
• You-Ming Huang,
• Gang Zou and
• Gang Zhao

Beilstein J. Org. Chem. 2016, 12, 725–731, doi:10.3762/bjoc.12.72

• , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, People’s Republic of China 10.3762/bjoc.12.72 Abstract A highly enantioselective α-amination of 3-substituted oxindoles with azodicarboxylates catalyzed by amino acids-derived chiral phosphine

• base to participate in the catalytic cycle. In 2015, we reported a novel asymmetric dual-reagent catalysis strategy based on these chiral phosphine catalysts [42], in which the zwitterion in situ generated from the chiral phosphine and methyl acrylate acted as an efficient catalyst for the asymmetric

• (diethyl azodicarboxylate, 2a) was selected as the model reaction for the evaluation of chiral phosphine catalysts (Table 1). Using bifunctional thiourea catalysts 4a and 4b, the reaction proceeded smoothly at room temperature to afford the product 3a in good yields, albeit with low enantiomeric excesses

(Thio)urea-mediated synthesis of functionalized six-membered rings with multiple chiral centers

• Giorgos Koutoulogenis,
• Nikolaos Kaplaneris and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2016, 12, 462–495, doi:10.3762/bjoc.12.48

• ion intermediate through a stabilizing cation–π-interaction. They came to this conclusion, after an extensive catalyst screening. In 2014, Shi and co-workers presented the synthesis of products 243, utilizing substrates 244 and α,β-unsaturated aldehyde 245. Chiral phosphine organocatalyst 246 was

Enantioselective [3 + 2] annulation of α-substituted allenoates with β,γ-unsaturated N-sulfonylimines catalyzed by a bifunctional dipeptide phosphine

• Huanzhen Ni,
• Weijun Yao and
• Yixin Lu

Beilstein J. Org. Chem. 2016, 12, 343–348, doi:10.3762/bjoc.12.37

• ; enantioselective; Introduction Over the past decade, chiral phosphine catalysts have been utilized extensively for the construction of a broad range of synthetically useful molecular structures [1][2][3][4][5][6][7][8][9][10][11][12][13]. Since the initial discovery of phosphine-catalyzed [3 + 2] annulation of

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

• synthesis of the antimicobacterial agent erogorgiaene (Scheme 12) [31]. One of the key steps of this synthesis involved the conversion of the bicyclic extended Michael acceptor 44 to 45 through a 1,4-selective copper-catalyzed ACA. Copper(I) triflate and chiral phosphine ligand L10 enabled this

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

• William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

• differences in rates of diastereomer decomposition. Calculation of acylphosphonite inversion barrier. As described in the Introduction, inversion barriers for phosphines, acylphosphines, and phosphites are known. These were calculated first for validation of the method. The structures of chiral phosphine 18

Phosphinocyclodextrins as confining units for catalytic metal centres. Applications to carbon–carbon bond forming reactions

• Matthieu Jouffroy,
• Rafael Gramage-Doria,
• David Sémeril,
• Dominique Armspach,
• Dominique Matt,
• Werner Oberhauser and
• Loïc Toupet

Beilstein J. Org. Chem. 2014, 10, 2388–2405, doi:10.3762/bjoc.10.249

• to enantioselectivity, only one chiral mono-P(III) ligand [30][31][32] has so far shown some potential in the notoriously challenging, but industrially relevant asymmetric hydroformylation [33][34][35][36][37]. Recently, we have synthesised a new type of chiral phosphine ligand (HUGPHOS-1 [38] and

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

• carbonates, Michael additions, γ-umpolung additions, and acylations of alcohols. Keywords: asymmetric catalysis; chiral phosphine; nucleophilic; organocatalysis; organophosphorus; synthesis; Introduction During the past two decades, tertiary phosphine catalysts have been applied extensively in a wide range

• developments in nucleophilic chiral phosphine-catalyzed asymmetric reactions, including annulations of allenes, ketenes, alkynes, and Morita–Baylis–Hillman (MBH) carbonates with activated alkenes and imines, allylic substitution of MBH acetates and carbonates, Michael additions, γ-umpolung additions, and

• acylations of alcohols. Our discussion is organized according to the structural features of the chiral phosphines, the reaction types, and the nature of the substrate. Because chiral phosphine-promoted Rauhut–Currier (RC) reactions [9][10] and MBH/aza-MBH reactions [21][22][23][24][25][26] have been

Rational design of cyclopropane-based chiral PHOX ligands for intermolecular asymmetric Heck reaction

• Marina Rubina,
• William M. Sherrill,
• Alexey Yu. Barkov and
• Michael Rubin

Beilstein J. Org. Chem. 2014, 10, 1536–1548, doi:10.3762/bjoc.10.158

• the isomerization were identified. It was shown that the nature of this isomerization is different from that demonstrated previously using chiral diphosphine ligands. Keywords: asymmetric catalysis; chiral phosphine ligands; cyclopropane; Heck reaction; organophosphorus; transition metal catalysis

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

• copper catalyst [56]. The product 14b was obtained in good yield with retention of configuration at the phosphorus center (Scheme 9). Other chiral phosphine boranes 13 were reacted similarly. This protocol is limited to the availability of these chiral substrates. Protocols for the enantioselective cross

• -poor diarylphosphines 25c. The chiral phosphine oxides 54 were obtained in high yield with excellent stereoselectivities. In the proposed mechanism the catalyst 55 acts as a base toward the diarylphosphine 25c. Some other examples of palladium-catalyzed asymmetric hydrophosphination are the addition of

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

• chiral phosphine ligands and AgOAc via bidentate chelation of a properly substituted aldimine. Chiral phosphine–silver(I) complexes are emerging as a valuable tool for carbon–carbon bond forming reactions. These catalysts are effective in promoting enantioselective allylations, aldol reactions, Mannich

Synthesis of axially chiral gold complexes and their applications in asymmetric catalyses

• Yin-wei Sun,
• Qin Xu and
• Min Shi

Beilstein J. Org. Chem. 2013, 9, 2224–2232, doi:10.3762/bjoc.9.261

• hydroamination of allenes by using a variety of chiral phosphine–Au(I) complexes [57][58][59][60][61][62][63]. On the other hand, the intramolecular hydroamination of olefins is a more important reaction in organic synthesis and has been widely reported [64][65][66][67][68]. Recently, the enantioselective

Organocatalyzed enantioselective desymmetrization of aziridines and epoxides

• Ping-An Wang

Beilstein J. Org. Chem. 2013, 9, 1677–1695, doi:10.3762/bjoc.9.192

• enantioselectivities. In the presence of some achiral phase-transfer catalysts or phosphines such as TBAB and P(t-Bu)3, the vicinal chlorohydrins were obtained in high yields. Up to now, three classes of organocatalysts including chiral phosphoramides, chiral phosphine oxides, and chiral pyridine N-oxides were used in

• /silicon cation through the oxygen atom of P=O and the coordination with the silicon atom of the nucleophiles. It can be deduced that the chiral phosphine oxides can also play a role for the activation of SiCl4 and serve as catalysts for the desymmetrization of meso-epoxides. The first example of a chiral

• phosphine oxide-catalyzed asymmetric ring-opening of meso-epoxides has been realized by Nakajima [83] and co-workers and proved to be very effective. They have prepared a chiral phosphine oxide BINAPO (OC-63) based on a binaphthyl-skeleton, which was utilized as an organocatalyst for the enantioselective

Chiral multifunctional thiourea-phosphine catalyzed asymmetric [3 + 2] annulation of Morita–Baylis–Hillman carbonates with maleimides

• Hong-Ping Deng,
• De Wang,
• Yin Wei and
• Min Shi

Beilstein J. Org. Chem. 2012, 8, 1098–1104, doi:10.3762/bjoc.8.121

• ] annulation catalyzed by chiral phosphines, Zhang and co-workers first reported the asymmetric [3 + 2] annulation of allenoates with acrylates catalyzed by a bicyclic chiral phosphine in 1997 [21]. Moreover, Fu [22][23][24], Marinetti [25][26][27][28], Lu [29][30][31] and other researchers [32][33][34][35][36