174757-35-8

Basic information

• Product Name: Bicyclo[2.2.1]hept-5-ene-2-carboxaldehyde, 2-ethyl-, (1S,2S,4S)- (9CI)
• Synonyms: Bicyclo[2.2.1]hept-5-ene-2-carboxaldehyde, 2-ethyl-, (1S,2S,4S)- (9CI)
• CAS NO: 174757-35-8
• Molecular Formula: C10H14O
• Molecular Weight: 150.21756
• Product Categories: ALDEHYDE
• Mol File: 174757-35-8.mol

Chemical Properties

• Appearance: /
• CAS DataBase Reference: Bicyclo[2.2.1]hept-5-ene-2-carboxaldehyde, 2-ethyl-, (1S,2S,4S)- (9CI)(CAS DataBase Reference)
• NIST Chemistry Reference: Bicyclo[2.2.1]hept-5-ene-2-carboxaldehyde, 2-ethyl-, (1S,2S,4S)- (9CI)(174757-35-8)
• EPA Substance Registry System: Bicyclo[2.2.1]hept-5-ene-2-carboxaldehyde, 2-ethyl-, (1S,2S,4S)- (9CI)(174757-35-8)

Safety Data

• Hazardous Substances Data: 174757-35-8(Hazardous Substances Data)

Upstream product

• 922-63-4 ethylacrolein 
• 542-92-7 cyclopenta-1,3-diene 

Relevant articles and documents

Arene-Ruthenium Complexes of 1,1′-Bis(ortho-carborane): Synthesis, Characterization, and Catalysis

Deprotonation of 1,1′-bis(ortho-carborane) with nBuLi in THF followed by reaction with [RuCl2(p-cymene)]2 affords, in addition to the known compound [Ru(κ3-2,2′,3′-{1-(1′-closo-1′,2′-C2B10H10)-closo-1,2-C2B10H10)}(p-cymene)] (I), a small amount of a new species, [Ru(κ3-2,2′,11′-{1-(7′-nido-7′,8′-C2B9H11)-closo-1,2-C2B10H10)}(p-cymene)] (1a), with two B-agostic B-H?Ru bonds, making the bis(carborane) unit a closo-nido-X(C)L2 ligand, a previously unreported bonding mode. Similar species were also formed with arene = benzene (1b), mesitylene (1c), and hexamethylbenzene (1d), although in the last two cases the metallacarborane-carborane species [1-(1′-closo-1′,2′-C2B10H11)-3-(arene)-closo-3,1,2-RuC2B9H10)], 2c and 2d, were also isolated. With the bis(ortho-carborane) transfer reagent [Mg(κ2-2,2′-{1-(1′-closo-1′,2′-C2B10H10)-closo-1,2-C2B10H10)}(DME)2], the target compounds [Ru(κ3-2,2′,3′-{1-(1′-closo-1′,2′-C2B10H10)-closo-1,2-C2B10H10)}(arene)], 4b and 4d, were prepared in reasonable-to-good yields, although for arene = benzene and mesitylene small amounts of the unique paramagnetic species [{Ru(arene)}2(μ-Cl)(μ-κ4-2,2′,3,3′-{1-(1′-closo-1′,2′-C2B10H9)-closo-1,2-C2B10H9})], 3b and 3c, were also formed. In compounds 3, the bis(carborane) acts as a closo-closo-X4(C,C′,B,B′) ligand to the Ru2 unit. In I, 4b, and 4d, the B-agostic B-H?Ru bond is readily cleaved by MeCN, affording compounds [Ru(κ2-2,2′-{1-(1′-closo-1′,2′-C2B10H10)-closo-1,2-C2B10H10})(arene)(NCMe)] (5a, 5b, and 5d) and suggesting that I, 4b, and 4d could act as Lewis acid catalysts, which is subsequently shown to be the case for the Diels-Alder cycloaddition reactions between cyclopentadiene and methacrolein, ethylacrolein and E-crotonaldehyde. All new species were characterized by multinuclear NMR spectroscopy and 1a, 1c, 1d, 2c, 2d, 3b, 3c, 4b, 4d, 5a, 5b, and 5d were also characterized crystallographically.

Diazepane Carboxylates as Organocatalysts in the Diels–Alder Reaction of α-Substituted Enals

Ethyl diazepane carboxylate efficiently catalyzes the Diels–Alder cycloaddition of α-substituted-α,β-unsaturated aldehydes via iminium ion organocatalysis. The reaction is applicable to a range of dienes and dienophiles and generally proceeds at room temperature in the presence of 5 mol-% catalyst and 2.5 mol-% triflic acid co-catalyst. The incorporation of a stereogenic center on the diazepane backbone in combination with a menthyl carbamate produces a catalyst which affords enantioselectivities of 70–95 % ee for the cycloaddition of cyclopentadiene with a range of dienophiles. The enantioselectivity is rationalized via a transition state in which electrostatic stabilization by the carboxylate directs the diene to the more hindered face of the dienophile.

Remote Tris(pentafluorophenyl)borane-Assisted Chiral Phosphoric Acid Catalysts for the Enantioselective Diels-Alder Reaction

Tris(pentafluorophenyl)borane-assisted chiral supramolecular phosphoric acid catalysts were developed for the model Diels-Alder reaction of α-substituted acroleins with cyclopentadiene. Two remotely coordinated tris(pentafluorophenyl)boranes should help to increase the Bronsted acidity of the active center in the supramolecular catalyst and create effective bulkiness for the chiral cavity. The prepared supramolecular catalysts acted as not only conjugated Bronsted acid-Bronsted base catalysts but also bifunctional Lewis acid-Bronsted base catalysts with the addition of a central achiral Lewis acid source such as catecholborane.

Enantioselective Diels-Alder Reaction Induced by Chiral Supramolecular Lewis Acid Catalysts Based on CN?B and PO?B Coordination Bonds

Chiral supramolecular boron Lewis acid catalysts were prepared from chiral 3-phosphoryl-1,1′-bi-2-naphthols, (2-cyanophenyl)boronic acids, and tris(pentafluorophenyl)borane, bound through CN···B and PO···B coordination bonds. In particular, the coordinated tris(pentafluorophenyl)boranes increase the Lewis acidity of the active center in the manner of a Lewis acid assisted Lewis acid catalyst system. A possible cavity in these catalysts was highly suitable for several Diels-Alder probe reactions of acroleins with cyclic or acyclic dienes, which gave the corresponding adducts in good to high yields and high enantio-selectivities.

Asymmetric Diels–Alder Reaction of α-Substituted and β,β-Disubstituted α,β-Enals via Diarylprolinol Silyl Ether for the Construction of All-Carbon Quaternary Stereocenters

The asymmetric Diels–Alder reaction of α-substituted acrolein proceeds in the presence of the trifluoroacetic acid salt of trifluoromethyl-substituted diarylprolinol silyl ether to afford the exo-isomer with both excellent diastereoselectivity and high en

Enantioselective catalysts based on the chiral fragment (η5-C5Me5)Ir(Prophos) for Diels-Alder reactions

The aqua complex (SIr,RC)-[(η5-C 5Me5)Ir(Prophos)(H2O)][SbF6] 2 [Prophos = (R)-propane-1,2-diyl-bis(diphenylphosphane)] is an active precursor for the asymmetric Diels-Alder reaction of acyclic enals with cyclopentadiene, 2,3-dimethylbutadiene and isoprene. Enantioselectivities up to 78% ee are achieved. The intermediate Lewis acid-dienophile complex (S Ir,RC)-[(η5-C5Me 5)Ir(Prophos)(ethyl acrolein)][SbF6]2 has been isolated and completely characterized, including the X-ray crystal structure determination. Structural parameters indicate that the disposition of the coordinated dienophile is controlled by CH/π attractive interactions established between a phenyl group of the Prophos ligand and the aldehyde proton of the coordinated enal. Proton NMR data indicate that these interactions are maintained in solution. From diffractometric and spectroscopic data, the origin of the enantioselectivity is discussed.

Catalytic enantioselective construction of all-carbon quaternary stereocenters by an organocatalytic Diels-Alder reaction of α-substituted α,β-unsaturated aldehydes

A binaphthyl-based primary amine (R)-3d was designed for the Diels-Alder reaction of α-substituted α,β-unsaturated aldehydes; in the presence of the TfOH salt of (R)-3d, the Diels-Alder reaction of α-substituted α,β-unsaturated aldehydes with cyclopentadi

A new cationic, chiral catalyst for highly enantioselective Diels-Alder reactions

(Matrix presented) The Diels-Alder reaction of cyclopentadiene and 2-methacrolein is catalyzed by a chiral Lewis acid to form the exo adduct in 96% yield and 96% ee.

An application of electronic asymmetry to highly enantioselective catalytic Diels-Alder reactions

The compounds (RRu)-[CyRuCl(S)-BINPO]SbF6 and [CyRuCl(S)-TolBINPO]SbF6 (Cy = η6-cymene), were synthesized from (CyRuCl2)2 and the appropriate non-C2-symmetric bisphosphine monoxide ligands (S)BINPO and (S)-TolBINPO (BINPO = 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) in the presence of NaSbF6. When these complexes were mixed with AgSbF6 the resulting Lewis acids catalyzed the Diels-Alder cycloaddition of cyclopentadiene and methacrolein. The product (2S)-methylbicyclo[2.2.1]hept-5-ene-2-carboxaldehyde was obtained with excellent diastereoselectivity (up to 99%) and enantioselectivity (up to 99%) in several cases. When the complexes containing the analogous C2-symmetric bisphosphine ligands (S)-BINAP and (S)-TolBINAP were employed as catalysts, the Diels-Alder cycloadducts were obtained with much lower enantioselectivity (19 to 50%) for the opposite antipode. Although some of the effect may arise from chelate ring size change, much of the enhanced stereoselectivity of (RRu)-[CyRuCl(S)-BINPO]SbF6 and [CyRuCl(S)-TOlBINPO]SbF6 can be attributed to the electronic asymmetry at the stereogenic Ru center.

Design of bronsted acid-assisted chiral Lewis acid (BLA) catalysts for highly enantioselective Diels-Alder reactions

Bronsted acid-assisted chiral Lewis acid (BLA) was highly effective as a chiral catalyst for the enantioselective Diels-Alder reaction of both α- substituted and α-unsubstituted α,β-enals with various dienes. Hydroxy groups in optically active binaphthol derivatives and boron reagents with electron-withdrawing substituents were used as Bronsted acids and Lewis acids, respectively. Intramolecular Bronsted acids in a chiral BLA catalyst played an important role in accelerating the rate of Diels-Alder reactions and in producing a high level of enantioselectivity. In particular, excellent enantioselectivity was achieved due to intramolecular hydrogen bonding interaction and attractive π-π donor-acceptor interaction in the transition-state assembly by hydroxy aromatic groups in a chiral BLA catalyst.