Synthesis of Pseudo-geminal-, Pseudo-ortho-, andortho-Phosphinyl-oxazolinyl-[2.2]paracyclophanes for Use as Ligands in Asymmetric Catalysis

Whelligan, Daniel K.; Bolm, Carsten

doi:10.1021/jo060668h

Cited by 86 publications

(32 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…So far, planar-chiral [2.2]paracyclophanes have been predominately recognized as suitable scaffolds for phosphane [11] and heterocyclic carbene ligands. [12] Only lately have their applications as organocatalysts been reported.…”

Section: Resultsmentioning

confidence: 99%

Planar‐Chiral Bis‐silanols and Diols as H‐Bonding Asymmetric Organocatalysts

et al. 2012

Self Cite

View full text Add to dashboard Cite

The successful development of planar‐chiral bis‐silanols 3a–d and their application as asymmetric organocatalysts in hetero‐Diels–Alder (HDA) reactions is described. All precursors were easily prepared by addition of commerically available silyl electrophiles to a dilithiated [2.2]paracyclophane derivative followed by silane oxidations. The analogous bis‐carbinols 7a–c have been prepared by addition of suitable Grignard reagents to bis‐methoxycarbonyl derivative 6. Both racemic as well as enantiopure planar‐chiral bis‐silanols and bis‐carbinols were obtained in good yields. The catalytic activities of the bis‐silanols were analyzed by monitoring HDA reactions between Rawal's diene and aldehydes by in situ IR spectroscopy and comparing the resulting data with those obtained in catalyses with the corresponding bis‐carbinol derivatives. The results show for the first time that planar‐chiral bis‐silanols with hydrogen‐bonding capabilities can be applied as asymmetric organocatalysts leading to enantiomerically enriched products.

show abstract

Section: Resultsmentioning

confidence: 99%

Planar‐Chiral Bis‐silanols and Diols as H‐Bonding Asymmetric Organocatalysts

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…The general P,P ‐ligand framework has been thoroughly studied, and extensively modified and combined with other transition‐metals for many other asymmetric catalytic transformations . Furthermore, mixed P,N ‐ligands such as oxazoline 3 or pyridine 4 as well as N , N ‐ligands such as bisoxazoline 5 have been synthesized. However, the synthesis of many of these ligands requires the introduction of space moieties that significantly alter the bite‐angle and mode of coordination.…”

Section: Figurementioning

confidence: 99%

Unprecedented One‐Pot Reaction towards Chiral, Non‐Racemic Copper(I) Complexes of [2.2]Paracyclophane‐Based P,N‐Ligands

Braun

Nieger

Bräse

2017

Chemistry A European J

View full text Add to dashboard Cite

Herein, we report a simple one-pot route to enantiopure copper(I) complexes featuring a unique [2.2]paracyclophane-based P,N-ligand system. Phosphine and pyridine moieties can be varied allowing the modular synthesis of these rigid and stable [2.2]paracyclophane-based P,N-ligands. These P,N-ligands are a new ligand class for different transition-metal complexes, which is shown exemplarily for palladium(II).

show abstract

“…An example of the synthesis of the phosphino-oxazolines containing both planar and central elements of chirality, but not derived from ferrocene, was reported by Bolm and co-workers [43]. The oxazoline ring was built in several steps as a side arm of the racemic [2,2]paracyclophane-derived carboxylic acid 24 and the unsubstituted [2,2]paracyclophane 27 (Scheme 10, parts A and B).…”

Section: Synthesis Of Pn-ligands Containing Features Of Two Major CLmentioning

confidence: 99%

Synthesis of Aminophosphines and Their Applications in Catalysis

Stepanova¹,

Smoliakova²

2012

COC

View full text Add to dashboard Cite

The review describes preparation of P,N-bidentate ligands without a P-N bond and their use in asymmetric catalysis. Diverse types of aminophosphines are considered with emphasis on P,N-ferrocene ligands, phosphino-oxazolines and phosphinopyridines. The following major synthetic approaches to aminophosphines and related compounds are summarized: (i) via lithiation, (ii) the use of Grignard reagents, (iii) nucleophilic substitution using metal phosphides, (iv) Staudinger method, (v) hydrophosphination of , -unsaturated carbonyl compounds, (vi) Cu-and Pd-catalyzed C-P bond formation reactions, and (vii) reactions of cyclopalladated complexes with metal phosphides and HPPh2. Highlights of aminophosphine applications in asymmetric synthesis include their use in hydrogenation, hydrosilylation, and hydroboration reactions as well as in various transformations leading to a C-C bond formation such as Suzuki coupling, Meerwein-Eschenmoser-Claisen rearrangement, Mukaiyama aldol reaction, Tsuji allylation and ethylene oligomerization.ligands in a number of metal-catalyzed transformations are presented. Synthesis and applications of aminophosphines with a P-N bond are not included in this review. Preparation of -aminophosphoryl compounds [22] as well as reactions leading to the C-P bond formation using diphenylphosphine oxide HP(O)Ph 2 and dialkyl phosphites (RO) 2 P(O)H (see, for example, recent reports of Keglevich [23,24]) are also outside of the scope of this review. MAJOR CLASSES OF AMINOPHOSPHINES WITHOUT A P-N BONDThe majority of reported P,N-ligands without a P-N bond can be divided into several major categories (Chart 1). The first group is based on the ligands derived from ferrocene. Representatives of this group have been the first examples of chiral P,N-ligands successfully applied in asymmetric catalysis [25]. The second major group includes phosphino-oxazolines (PHOX), which are among the most successful catalysts in metal-catalyzed asymmetric reactions [6,7,[26][27][28][29][30][31][32]. The third group consists of chiral aliphatic P,Nligands, which can be obtained by a modification of a naturally available chiral source, e.g. amino acids [33,34]. The fourth group is formed by structurally diverse binaphthyl derivatives, so-called MAP ligands, which combine axial chirality with soft and hard coordination properties of phosphorus and nitrogen atoms [35]. The next group worth mentioning is represented by P,N-ligands with the pyridine or quinoline framework, e.g. QUINAP [8,36]. Representatives of the last type of aminophosphines have either phosphorusor nitrogen-containing non-aromatic heterocycle [37,38]. Separately from these major groups stand the ligands with structural features from two or more of the aforementioned ligand types, e.g. oxazoline-ferrocene [39] or pyrrolidine-MAP-derivatives [10]. SYNTHETIC APPROACHES TO AMINOPHOSPHINESDevelopment of synthetic routes to aminophosphines without a P-N bond recently received a lot of attention due to a growing number of impressive applications of these ligands in a...

show abstract

Synthesis of Pseudo-geminal-, Pseudo-ortho-, andortho-Phosphinyl-oxazolinyl-[2.2]paracyclophanes for Use as Ligands in Asymmetric Catalysis

Cited by 86 publications

References 52 publications

Planar‐Chiral Bis‐silanols and Diols as H‐Bonding Asymmetric Organocatalysts

Planar‐Chiral Bis‐silanols and Diols as H‐Bonding Asymmetric Organocatalysts

Unprecedented One‐Pot Reaction towards Chiral, Non‐Racemic Copper(I) Complexes of [2.2]Paracyclophane‐Based P,N‐Ligands

Synthesis of Aminophosphines and Their Applications in Catalysis

Contact Info

Product

Resources

About