(Dhqd)2pyr

• CAS: 149725-81-5
• Catalog Number: ACM149725815
• Category: Main Products
• Molecular Weight: 881.11
• Molecular Formula: C₅₆H₆₀N₆O₄
• Synonyms: (DHQD)2Pyr, Hydroquinidine-2,5-diphenyl-4,6-pyrimidinediyl diether, 149725-81-5, 418951_ALDRICH, CTK8E7313
• IUPAC Name: 4-[(S)-[(2R,4S,5R)-5-ethyl-1-azabicyclo[2.2.2]octan-2-yl]-[6-[(S)-[(2R,4S,5R)-5-ethyl-1-azabicyclo[2.2.2]octan-2-yl]-(6-methoxyquinolin-4-yl)methoxy]-2,5-diphenylpyrimidin-4-yl]oxymethyl]-6-methoxyquinoline
• Canonical SMILES: CCC1CN2CCC1CC2C(C3=C4C=C(C=CC4=NC=C3)OC)OC5=C(C(=NC(=N5)C6=CC=CC=C6)OC(C7CC8CCN7CC8CC)C9=C1C=C(C=CC1=NC=C9)OC)C1=CC=CC=C1
• InChI Key: SWKRDCRSJPRVNF-DOGDSVMGSA-N
• Melting Point: 247-250ºC(lit.)
• EC Number: 604-699-9
• Exact Mass: 880.46800
• Hazard Statements: Xi
• H-Bond Acceptor: 10
• H-Bond Donor: 0
• Safety Description: S26-S36

Case Study

(DHQD)2PYR for Catalytic Asymmetric Semi-Pinacol Rearrangement

Wang, Shao-Hua, et al. Chemical Communications, 2014, 50(19), 2393-2408.

An organocatalytic enantioselective fluorination/semi-pinacol rearrangement has been reported. By employing the bis-quinine derivative (DHQ)2PYR as the catalyst (10-20 mol%) and NSFI as the fluorinating agent, the fluorination/semi-pinacol rearrangement was successfully conducted at a low temperature of 10 °C, yielding chiral α-oxaquaternary β-fluoro-ketones with significantly improved enantioselectivities (36-90% ee) and higher isolated yields (29-73%) in most instances. Notably, the absolute configuration of the newly formed stereogenic center could be controlled by the choice of catalyst. The use of (DHQD)2PYR produced products with (αS, βS) stereochemistry, while (DHQ)2PYR resulted in the inverse (αR, βR) stereochemistry, achieving comparable ee values but slightly lower yields.
Building on this success, the catalytic asymmetric Cl+-induced rearrangement of semi-pinacol was investigated. Extensive optimization of reaction conditions revealed that using (DHQ)2PYR or (DHQD)2PYR as catalysts (10 mol%) and DCDMH as the Cl+ reagent enabled an asymmetric chlorination/semi-pinacol rearrangement in an acidic medium (NBLP, 10%) at temperatures of 50 or 70 °C. This process generated α-oxaquaternary β-chloro-ketones with good to high enantioselectivities (74-99% ee) and moderate yields (40-76%). It is important to note that (DHQ)2PYR provided lower yields and enantioselectivities compared to (DHQD)2PYR. Additionally, incorporating the acidic additive NBLP alongside 5 Å molecular sieves significantly accelerated the reaction rate, although the overall yield and enantioselectivity saw only slight improvements.

(DHQD)2PYR for the Catalytic Enantioselective Synthesis of α-(Benzylamino)Cyclobutanones

Melis, Nicola, et al. European Journal of Organic Chemistry, 2015, 2015(20), 4358-4366.

Starting from readily available racemic α-hydroxycyclobutanone and various benzylamines, an organocatalytic enantioselective synthesis of α-(benzylamino)cyclobutanone was achieved by adopting a tandem condensation/intramolecular rearrangement/proton transfer reaction catalyzed by a cinchona alkaloid derivative ((DHQD)2PYR).
· General Procedure for α-Benzylamination of α-Hydroxycyclobutanones
Add benzylamine (0.224 mmol) dropwise to freshly distilled α-hydroxycyclobutanone (0.058 g, 0.669 mmol) and (DHQD)2PYR (0.0395 g, 0.0448 mmol) in dry 1,4-dioxane (0.5 mL) at room temperature. It was stirred for 0.5- 18 hours. Subsequently, the crude reaction mixture was subjected to flash column chromatography (silica gel; hexane/ether, 5:1 to 1:1) to isolate the pure product. The racemates were created by 4-(dimethylamino)pyridine (DMAP) as a catalyst.
· Substrate Scope Regarding Aromatic Ring Substituents
To evaluate the scope of this transformation, experiments were conducted by varying the substituents on the dibenzylamine substrate. High enantioselectivities were achieved with a series of dibenzylamines containing electron-withdrawing groups on the aromatic ring. For dibenzylamines 2b-2h, which have one electron-withdrawing substituent at the para position, the desired α-aminocyclobutanones 3b-3h were obtained in high yields (up to 94%) with enantioselectivities reaching 87:13 e.r. A representative dibenzylamine with a meta substituent (2i) performed similarly well, yielding 77% and an enantiomeric ratio of 78:22. However, the ortho-substituted dibenzylamine 2j resulted in a lower yield of 48% and an enantiomeric ratio of only 56:44 for the desired product 3j.

Custom Q&A

What is the molecular formula of keyword (Dhqd)2pyr?

The molecular formula of keyword (Dhqd)2pyr is C56H60N6O4.

What are the synonyms for keyword (Dhqd)2pyr?

The synonyms for keyword (Dhqd)2pyr are (DHQD)2-PYR and 4-[(S)-[(2R,4S,5R)-5-ethyl-1-azabicyclo[2.2.2]octan-2-yl]-[6-[(S)-[(2R,4S,5R)-5-ethyl-1-azabicyclo[2.2.2]octan-2-yl]-(6-methoxyquinolin-4-yl)methoxy]-2,5-diphenylpyrimidin-4-yl]oxymethyl]-6-methoxyquinoline.

What is the molecular weight of keyword (Dhqd)2pyr?

The molecular weight of keyword (Dhqd)2pyr is 881.1 g/mol.

When was keyword (Dhqd)2pyr created?

Keyword (Dhqd)2pyr was created on October 25, 2006.

When was keyword (Dhqd)2pyr last modified?

Keyword (Dhqd)2pyr was last modified on October 21, 2023.

What is the IUPAC name of keyword (Dhqd)2pyr?

The IUPAC name of keyword (Dhqd)2pyr is 4-[(S)-[(2R,4S,5R)-5-ethyl-1-azabicyclo[2.2.2]octan-2-yl]-[6-[(S)-[(2R,4S,5R)-5-ethyl-1-azabicyclo[2.2.2]octan-2-yl]-(6-methoxyquinolin-4-yl)methoxy]-2,5-diphenylpyrimidin-4-yl]oxymethyl]-6-methoxyquinoline.

What is the InChIKey of keyword (Dhqd)2pyr?

The InChIKey of keyword (Dhqd)2pyr is SWKRDCRSJPRVNF-DOGDSVMGSA-N.

What is the Canonical SMILES representation of keyword (Dhqd)2pyr?

The Canonical SMILES representation of keyword (Dhqd)2pyr is CCC1CN2CCC1CC2C(C3=C4C=C(C=CC4=NC=C3)OC)OC5=C(C(=NC(=N5)C6=CC=CC=C6)OC(C7CC8CCN7CC8CC)C9=C1C=C(C=CC1=NC=C9)OC)C1=CC=CC=C1.

What is the CAS number of keyword (Dhqd)2pyr?

The CAS number of keyword (Dhqd)2pyr is 149725-81-5.

What is the hydrogen bond acceptor count of keyword (Dhqd)2pyr?

The hydrogen bond acceptor count of keyword (Dhqd)2pyr is 10.