The synthesis of α-aryl-α-aminophosphonates and α-aryl-α-aminophosphine oxides by the microwave-assisted Pudovik reaction

• Erika Bálint,
• Ádám Tajti,
• Anna Ádám,
• István Csontos,
• Konstantin Karaghiosoff,
• Mátyás Czugler,
• Péter Ábrányi-Balogh and
• György Keglevich

Beilstein J. Org. Chem. 2017, 13, 76–86, doi:10.3762/bjoc.13.10

• the dialkyl phosphite were applied [43][44][45][46][47][48][49][50][51][52]. The synthesis of α-aryl-α-aminophosphine oxides by the addition of secondary phosphine oxides to imines is much less studied. Only a few publications were found and the reported reactions were performed in solvent (in DEE

Catalytic Wittig and aza-Wittig reactions

• Zhiqi Lao and
• Patrick H. Toy

Beilstein J. Org. Chem. 2016, 12, 2577–2587, doi:10.3762/bjoc.12.253

• covers the field of related catalytic aza-Wittig reactions that are catalyzed by both phosphine oxides and phosphines. Keywords: aza-Wittig reactions; catalysis; phosphines; phosphine oxides; reduction; silanes; Wittig reactions; Introduction The Wittig reaction is a venerable transformation for

• Wittig reaction distils down to identifying and implementing selective reducing conditions that enables the necessary catalyst redox cycling, yet does not reduce either the starting materials or the desired alkene-containing product. Arsine and telluride-catalyzed reactions As phosphine oxides are

• generally very stable and relatively difficult to reduce, the group of Yao-Zeng Huang used their prior findings that arsonium ylides can participate in Wittig-type reactions. Further they found that arsine oxides can be reduced using much milder reaction conditions compared to phosphine oxides. They

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

• enatiofacial selectivity, the use of a cyclic imide ensured exclusive formation of the Z-enolate. During optimization, it was found that an N-aryl group containing 2,6-disubstitution was crucial for obtaining high levels of enantioselectivity. Addition of a variety of bis-aryl secondary phosphine oxides

• nitroalkene [67]. α,β-Unsaturated phosphonates and phosphine oxides Transition metal catalysts In 2006, Hayashi and co-workers reported the first conjugate addition–enantioselective protonation of allenes 165 bearing a phosphine oxide (Scheme 39) [68]. Incorporation of the phosphine oxide allowed for

• enantioselective Friedel–Crafts addition of pyrroles to imides 84. Kobayashi’s enantioselective addition of malonates to α-substituted N-acryloyloxazolidinones. Chen and Wu’s enantioselective addition of thiophenol to N-methacryloyl benzamide. Tan’s enantioselective addition of secondary phosphine oxides and

Aerobic addition of secondary phosphine oxides to vinyl sulfides: a shortcut to 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl)phosphine oxides

• Svetlana F. Malysheva,
• Alexander V. Artem’ev,
• Nina K. Gusarova,
• Nataliya A. Belogorlova,
• Alexander I. Albanov,
• C. W. Liu and
• Boris A. Trofimov

Beilstein J. Org. Chem. 2015, 11, 1985–1990, doi:10.3762/bjoc.11.214

• Chemistry, National Dong Hwa University, Hualien 97401, Taiwan 10.3762/bjoc.11.214 Abstract Secondary phosphine oxides react with vinyl sulfides (both alkyl- and aryl-substituted sulfides) under aerobic and solvent-free conditions (80 °C, air, 7–30 h) to afford 1-hydroxy-2-(organosulfanyl)ethyl(diorganyl

• )phosphine oxides in 70–93% yields. Keywords: addition; green method; phosphine oxides; regioselectivity; vinyl sulfides; Findings Tertiary phosphines and phosphine chalcogenides are important organophosphorus compounds that are widely used in industry, organic synthesis, polymer science, medicinal and

• %). The substrate scope includes both EDG- and EWG-substituted alkenes [27][28][29]. In this letter, we report our serendipitous finding that secondary phosphine oxides 1a–f under aerobic conditions (air, 80 °C, 7–18 h) easily add to vinyl sulfides 2a–c to give unknown 1-hydroxy-2-(organosulfanyl)ethyl

Synthesis of γ-hydroxypropyl P-chirogenic (±)-phosphorus oxide derivatives by regioselective ring-opening of oxaphospholane 2-oxide precursors

• Iris Binyamin,
• Shoval Meidan-Shani and
• Nissan Ashkenazi

Beilstein J. Org. Chem. 2015, 11, 1332–1339, doi:10.3762/bjoc.11.143

• Iris Binyamin Shoval Meidan-Shani Nissan Ashkenazi Department of Organic Chemistry, IIBR-Israel Institute for Biological Research, P.O. Box 19, Ness Ziona, 74100, Israel 10.3762/bjoc.11.143 Abstract The synthesis of P-chirogenic (±)-phosphine oxides and phosphinates via selective nucleophilic

• ; oxaphospholanes; phosphinates; phosphine oxides; Introduction Organophosphorus compounds containing phosphorus to carbon bond(s) are widely used in organic transformations. Textbook examples are the Wittig and the Horner–Wadsworth–Emmons reactions. Moreover, the vast majority of ligands used in organometallic

• various Grignard reagents. Indeed, in all cases, the attack on the phosphorus atom led exclusively to ring opening via endocyclic P–O bond cleavage and formation of a new P–C bond, yielding phosphinates and phosphine oxides with three different substituents on the phosphorus atom. Results and Discussion

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

• enantioselectivity. In 2010, Wang and co-workers expanded their methodology to the 1,4-addition of phosphine oxides. Similar to their previous work, this reaction provided the products in high yields and enantioselecitives [266] (Scheme 40). 2.5 ECA employing organocatalysts Organocatalysts have become powerful

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

• acylphosphonite would require different nucleoside moieties. One example can be found in the literature of a non-Arbuzov route leading to the dinucleoside analog of 3 where as reported by Hata et al., 3a [41] gives 3b via sequential coupling [42][43] (Scheme 1). While the deoxygenation of phosphine oxides is

P(O)R₂-directed Pd-catalyzed C–H functionalization of biaryl derivatives to synthesize chiral phosphorous ligands

• Rong-Bin Hu,
• Hong-Li Wang,
• Hong-Yu Zhang,
• Heng Zhang,
• Yan-Na Ma and
• Shang-dong Yang

Beilstein J. Org. Chem. 2014, 10, 2071–2076, doi:10.3762/bjoc.10.215

• group not only achieved the directing role but also acts as an important component unit of the C–H functionalized products. In this paper, we use the axially chiral biaryl phosphine oxides as substrates and report the synthesis of various chiral phosphorus ligands with high enantiomeric selectivity

Atherton–Todd reaction: mechanism, scope and applications

• Stéphanie S. Le Corre,
• Mathieu Berchel,
• Hélène Couthon-Gourvès,
• Jean-Pierre Haelters and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2014, 10, 1166–1196, doi:10.3762/bjoc.10.117

• secondary phosphine oxides) and a nucleophilic species (amines or alcohols) under AT reaction conditions. The reaction proceeded with a full stereoinversion at the phosphorus atom and led to the isolation of optically pure P–N coupling products with nearly quantitative yields (94%). The chemical structure

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

• [19]. This review will provide a general overview on phosphine synthesis over the last 10 to 15 years. Only reactions establishing a C–P bond will be discussed. The synthesis of phosphine-based polymers was not included [20]. Reactions involving pentavalent phosphorus derivatives (phosphine oxides

• oxidation, the perfluoroalkyl-substituted phosphine oxides 32 were obtained in low to moderate yields (15–51%) although full conversion was observed. The byproduct formed was reduced perfluoroalkane HCnF2n+1. Ethyl diazoacetate (33) was reacted with the secondary phosphine borane 13a in the presence of a

• -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

Concise, stereodivergent and highly stereoselective synthesis of cis- and trans-2-substituted 3-hydroxypiperidines – development of a phosphite-driven cyclodehydration

• Peter H. Huy,
• Julia C. Westphal and
• Ari M. P. Koskinen

Beilstein J. Org. Chem. 2014, 10, 369–383, doi:10.3762/bjoc.10.35

• to provide sufficient substance amounts for clinical tests [41][42]. Additionally, alternatives in reactions driven by the formation of phosphine oxides from phosphines (e.g. the Appel and Mitsunobu reaction) are highly desired to improve atom economy (reduced waste amounts) and to circumvent

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

• and the reaction time is up to 90 days! Chiral phosphoramides and phosphine oxides The first efficient organocatalyzed enantioselective desymmetrization of meso-epoxides was realized by Denmark [82] and colleagues in 1998 (Figure 13). In their initial experiments, various epoxides were attacked with

• /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

Metal–ligand multiple bonds as frustrated Lewis pairs for C–H functionalization

• Matthew T. Whited

Beilstein J. Org. Chem. 2012, 8, 1554–1563, doi:10.3762/bjoc.8.177

• observed [77]. As described above, FLPs of the Mδ−═Eδ+ variety can be very useful for inducing atom or group transfer from heterocumulenes or other polar multiple bonds such as those in phosphine oxides. Compared with early-metal Mδ−═Eδ+ FLPs, these sorts of complexes have the advantage of greater redox