1636-15-3Relevant academic research and scientific papers
Copper(I)-Catalyzed Asymmetric Synthesis of P-Chiral Aminophosphinites
Li, Yan-Bo,Tian, Hu,Xiao, Jun-Zhao,Yin, Liang,Zhang, Shuai
supporting information, (2022/02/17)
Herein, a copper(I)-catalyzed reaction of diarylphosphines and O-benzoyl hydroxylamines is developed. In the cases of symmetrical diarylphosphines, a series of aminophosphinites is prepared in high yields. In the cases of unsymmetrical diarylphosphines, an array of P-chiral aminophosphinites is synthesized in high yields with high enantioselectivity by using a copper(I)-(R,RP)-Ph-FOXAP complex as a chiral catalyst. Based on several control experiments and 31P NMR studies, a two-electron redox mechanism involving the dynamic kinetic asymmetric transformation of unsymmetrical diarylphosphines is proposed for the copper(I)-catalyzed asymmetric reaction. Finally, one representative P-chiral phosphoric amide generated through the oxidation with H2O2 is transformed to a chiral diarylphosphinate in high yield with retained enantioselectivity, which allows further transformations towards various P-chiral tertiary phosphines.
Mitsunobu Reaction Using Basic Amines as Pronucleophiles
Huang, Hai,Kang, Jun Yong
, p. 6604 - 6614 (2017/07/15)
A novel protocol for extending the scope of the Mitsunobu reaction to include amine nucleophiles to form C-N bonds through the utilization of N-heterocyclic phosphine-butane (NHP-butane) has been developed. Both aliphatic alcohols and benzyl alcohols are suitable substrates for C-N bond construction. Various acidic nucleophiles such as benzoic acids, phenols, thiophenol, and secondary sulfonamide also provide the desired products of esters, ethers, thioether, and tertiary sulfonamide with 43-93% yields. Importantly, C-N bond-containing pharmaceuticals, Piribedil and Cinnarizine, have been synthesized in one step from the commercial amines under this Mitsunobu reaction system.
Phosphino-amine (PN) Ligands for Rapid Catalyst Discovery in Ruthenium-Catalyzed Hydrogen-Borrowing Alkylation of Anilines: A Proof of Principle
Broomfield, Lewis Marc,Wu, Yichen,Martin, Eddy,Shafir, Alexandr
supporting information, p. 3538 - 3548 (2016/01/25)
A general synthetic protocol for the synthesis of simple phosphino-amine (PN) ligands is described with 19 ligands being isolated in good yields. High-throughput ligand screening uncovered the success of two of these ligands for aromatic amine alkylations via ruthenium-catalyzed hydrogen borrowing reactions. The combination of N,N'-bis(diphenylphosphino)-N,N′-dimethylpropylenediamine with a ruthenium(II) source and potassium hydroxide (15 mol%) is the optimal system for selective monobenzylations of aromatic amines (method A). Over 70% isolated yields have been achieved for the formation of 14 secondary aromatic amines under mild reaction conditions (120 C and 1.05 equivalents of benzyl alcohol). On the other hand, N,N-bis(diphenylphosphino)-isopropylamine was the ligand utilized for both selective monomethylation and monoethylation reactions of aromatic amines (method B). Here the alcohol is charged as both the reaction medium and substrate and 9 examples are disclosed with all isolated yields exceeding 70%. These methods have been applied to the synthesis of important synthetic building blocks based on aminoferrocene.
The reactivity of arylphosphorus acid amides under Birch reduction conditions
Stankevic, Marek,Wlodarczyk, Adam,Nieckarz, Damian
, p. 4351 - 4371 (2013/07/26)
Several classes of arylphosphorus acid amides have been tested in reactions with alkali metal solutions in liquid ammonia. The outcomes of such reactions depend on the structures of the starting materials. Generally, two processes-Birch reduction or cleavage of the P-aryl bond-can be operative. Diarylphosphinic amides tend to undergo double Birch reduction to afford bis(cyclohexadienyl)phosphinic amides. Copyright
Cleavage of P=O in the presence of P-N: Aminophosphine oxide reduction with in situ boronation of the PIII product
Kenny, Niall P.,Rajendran, Kamalraj V.,Jennings, Elizabeth V.,Gilheany, Declan G.
supporting information, p. 14210 - 14214 (2013/11/06)
In contrast to tertiary phos-phine oxides, the deoxygenation of aminophosphine oxides is effectively impossible due to the need to break the immensely strong and inert P=O bond in the presence of a relatively weak and more reactive P-N bond. This long-sta
Method for catalytic preparation of hydromorphone and hydrocodone
-
Page/Page column 6, (2008/12/06)
The present invention generally relates to catalysts of formula (III) [in-line-formulae][M(P(Ra)(Rb)N(Rc)(Rd))2Xn]mYp [/in-line-formulae]that selectively convert morphine/codeine to hydromorphone/hydrocodone, and methods of use thereof.
Efficient method for the preparation of carboxylic acid alkyl esters or alkyl phenyl ethers by a new-type of oxidation-reduction condensation using 2,6-dimethyl-1,4-benzoquinone and alkoxydiphenylphosphines
Shintou, Taichi,Kikuchi, Wataru,Mukaiyama, Teruaki
, p. 1645 - 1667 (2007/10/03)
A new-type of oxidation-reduction condensation proceeded smoothly to afford carboxylic acid alkyl esters or alkyl phenyl ethers in good to high yields by combined use of alkoxydiphenylphosphines (1) having primary, bulky secondary or tertiary alkoxy groups, a mild quinone-type oxidant such as 2,6-dimethyl-1,4-benzoquinone (DMBQ) and carboxylic acids or phenols. Generally, alkoxydiphenylphosphines were prepared easily from chlorodiphenylphosphine (2) and alcohols in the presence of pyridine, and were isolated by distillation. On the other hand, the phosphines 1 were also prepared in situ from N,N-dimethylaminodiphenylphosphine (3a) and primary or secondary alcohols while primary, bulky secondary or tertiary alkoxydiphenylphosphines were alternatively formed in situ by adding 2 to the "BuLi-treated alcohols in order to perform the above reactions by a one-pot procedure from alcohols and nucleophiles. The reaction of thus formed 1, DMBQ and carboxylic acids or phenols afforded the corresponding alkylated products, including hindered secondary and tertiary alkylated ones, in good to high yields at room temperature. In the case of using chiral secondary alcohols, the corresponding carboxylic acid alkyl esters were obtained as well in high yields with perfect inversion of stereochemistry by SN2 replacement.
Exploring the coordination chemistry and reactivity of dialkylamino- and bis(dialkylamino)-phosphines in the coordination sphere of metals
Dyer, Philip W.,Fawcett, John,Hanton, Martin J.,Kemmitt, Raymond D.W.,Padda, Ranbir,Singh, Narendra
, p. 104 - 113 (2007/10/03)
The coordination chemistry of a range of dialkylamino- and bis(dialkylamino)-phosphines, RxP(NR′2) 3-x (x = 1 or 2; R = Cl, Me, Ph, C6F5; R′ = Et, Pri), 1-7, has been studied and the resulting Group 6 tetracarbonyl and platinum dichloride bis(phosphine) complexes fully characterised. Subsequently, the reactivity of the P-N bonds of the metal-bound phosphines was probed. Treatment of R″OH (R″ = Me, Et, allyl) solutions of the bis(dialkylaminodiphenylphosphine) complexes with anhydrous HCl gas led to substitution of NR′2 by OR″; the resulting P-alkoxy complexes were isolated in excellent yields. Acidification of ethylene glycol solutions of the aminophosphine complexes afforded the corresponding bis(chlorodiphenylphosphine) derivatives. Following reaction of trans-[W(CO)4(P{NEt2}Ph2)2] with either aqueous HCl or H2SO4, trans-[W(CO) 4(P{OH}Ph2)2] could be isolated as its dichloromethane solvate in excellent yield (81%). Reactions of the bis(bis{dialkylamino} phenylphosphine) complexes under identical conditions yielded a range of unidentified products. Reactions of ligands 1-7 with [{RhCl(CO)2}2] and elemental selenium have been undertaken and the products used to assess the phosphines' donor capabilities. Depending on the substituents at phosphorus, either trans-diphosphine or cis-dicarbonyl complexes result from reaction with [{RhCl(CO)2} 2]. The sterically demanding phosphine P(NPr2 i)2Ph (5) proved unreactive towards complexation with metals, although its selenide could be prepared and isolated. In order to probe the observed lack of oxidation or complexation the molecular structure P(NPr2i)2(C6F5) has been determined by X-ray crystallography. The Royal Society of Chemistry 2003.
Aminodiphenylphosphanes: Isotope-induced chemical shifts 1Δ14/15N(31P), coupling constants 1J(31P,15N), and chemical shifts δ15N and δ31P
Contreras, Rosalinda,Grevy, Jean Michel,Garcia-Hernandez, Zureima,Goeizado-Rodriguez, Marisol,Wrackmeyer, Bernd
, p. 542 - 550 (2007/10/03)
A series of aminodiphenylphosphanes 1 [Ph2P-N(H)tBu (a), -NEt2 (b), -NiPr2 (c)], 2 [Ph2P-NHPh (a), -NH-2-pyridine (b), -NH-3-pyridine (c), -NH-4-pyridine (d), NH-pyrimidine (e), NH-2,6-Me2-C6/su
New chiral zwitterionic iron hydride complexes with 'ephosium' and 'valphosium' ligands
Brunet, Jean-Jacques,Chauvin, Remi,Chiffre, Jerome,Huguet, Sandrine,Leglaye, Pascale
, p. 117 - 123 (2007/10/03)
New chiral cationic phosphinite ligands based on ephedrine or valinol skeletons, and corresponding zwitterionic hydridotricarbonylferrate complexes are described. IR data indicate an unusual cis-H-Fe-P arrangement in these complexes, and NMR studies show
