2433-57-0

Upstream product

• 109-97-7 pyrrole 
• 91798-67-3 trans-4-(phenylsulfinyl)-3-buten-2-one 
• 1003-29-8 2-pyrrole aldehyde 
• 1439-36-7 1-triphenylphosphoranylidene-2-propanone 
• 67-64-1 acetone 

Relevant academic research and scientific papers

Rate dependence on inductive and resonance effects for the organocatalyzed enantioselective conjugate addition of alkenyl and alkynyl boronic acids to β-indolyl enones and β-pyrrolyl enones

Two key factors bear on reaction rates for the conjugate addition of alkenyl boronic acids to heteroaryl-appended enones: the proximity of inductively electron-withdrawing heteroatoms to the site of bond formation and the resonance contribution of available heteroatom lone pairs to stabilize the developing positive charge at the enone β-position. For the former, the closer the heteroatom is to the enone β-carbon, the faster the reaction. For the latter, greater resonance stabilization of the benzylic cationic charge accelerates the reaction. Thus, reaction rates are increased by the closer proximity of inductive electron-withdrawing elements, but if resonance effects are involved, then increased rates are observed with electron-donating ability. Evidence for these trends in isomeric substrates is presented, and the application of these insights has allowed for reaction conditions that provide improved reactivity with previously problematic substrates.

A Novel Pseudo-Three-Component Synthetic Strategy for the Synthesis of 1,6-Dihydroazaazulenes via Cyclization of Pyrrolyl-enones

A synthetic novel strategy involving a pseudo-three-component reaction to obtain 1,6-dihydroazaazulenes derivates via cyclization of pyrrolyl-enones was developed. This reaction is carried out under mild conditions from simple starting materials and catal

Isothiourea-catalysed enantioselective pyrrolizine synthesis: Synthetic and computational studies

The catalytic enantioselective synthesis of a range of cis-pyrrolizine carboxylate derivatives with outstanding stereocontrol (14 examples, >95:5 dr, >98:2 er) through an isothiourea-catalyzed intramolecular Michael addition-lactonisation and ring-opening

A general method for the enantioselective synthesis of α-chiral heterocycles

The enantioselective formation of stereocenters proximal to unprotected heterocycles has been accomplished. Thus, vinyl boronic acids are added to heterocycle-appended enones via a modified-BINOL catalyst. Catalyst design was key to enable a general reaction. High yields and useful er's are observed for a host of common heteroaryls.

Electron deficiency of aldehydes controls the pyrrolidine catalyzed direct cross-aldol reaction of aromatic/heterocyclic aldehydes and ketones in water

A synthetically useful pyrrolidine catalyzed direct cross-aldol reaction of aromatic/heterocyclic aldehydes with ketones in water affords the aldol addition product in up to 93% yield. Electrophilicity of the aldehydes controls the course of the reaction.

Replacement Substituent Constants for Simple Heterocycles

13C nmr absorptions are reported for the β-vinylic carbon atoms in 15 series of ethylenes bearing heterocyclic substituents.The data are used to establish the best single-parameter substituent constants, ?13, for the various heterocycles as replacements for para-substituted benzenes.Also reported are replacement dual substituent constants, including ?I and the various ?R scales needed in the Taft DSP treatment and those for F and R used in the Swain-Lupton treatment.Values of ?13, F, R, ?I, and ?Ro, respectively, for the various heterocycles as replacements for para-substituted benzenes are as follows: 2-furyl, -1.01 , 0.99, -2.51, 0.65, -0.60; 2-pyrryl, -2.53, 0.52, -5.09, -0.16, -0.62; 2-thienyl, -0.79, 2.49, -3.60, 1.82, -1.08; 3-thienyl, -0.40, 1.04, -1.57, 0.59, -0.39; 2-pyridyl, 0.88, 2.09, -0.24, 1.65, -0.45; 3-pyridyl, 0.60, 0.57, 0.63, 0.35, 0.04; and 4-pyridyl, 1.18, 1.22, 1.09, 0.92, -0.01.The DSP-NLR method of analysis is explored using electron demand parameters, ε, as determined for the vinylic side chains in para-substituted styrenes.

A Simple Synthesis of 3a-Azaazulen-6-one

3a-Azaazulen-6-one (1) has been obtained from 2-pyrrolecarbaldehyde on a 3-step route in a total yield of 13percent.

Novel Bicycloannulation via Tandem Vinylation and Intramolecular Diels-Alder Reaction of Five-Membered Heterocycles: A New Approach to Construction of Psoralen and Azapsoralen

trans-4-(Phenylsulfinyl)-3-buten-2-one (1) was found to undergo a new versatile addition-elimination reaction with five-membered compounds such as furans, pyrroles, imidazole, pyrazole, and 6-(dimethylamino)fulvene to give an excellent yield of the corresponding trans-4-aryl-3-buten-2-ones (3).The thermal reaction of the propargyl ethers 7a,b prepared from 3a,b gave a single intramolecular Diels-Alder adduct, 8a,b, in 59percent and 38percent yields, respectively.Treatment of 7a,b with t-BuOK in refluxing tert-butyl alcohol afforded another type of Diels-Alder adduct, 10a,b, in almost quantitative yields.This bicycloannulation strategy was applied to a new synthesis of psoralen which is of current interest due to its unique photoreactivity with DNA.The acid-catalyzed reaction of sulfoxide 12, prepared from ethyl acatoacetate in high yield, with furan gave 13 in 78percent yield.The intramolecular Diels-Alder reaction of the neopentyl acetal of 13 in the presence of Pd/C followed by acid hydrolysis afforded the tricyclic ketone 18 in 38percent yield.Baeyer-Villiger oxidation and dehydrogenation of 18 completed the synthesis of psoralen (11).Furthermore, hitherto unknown azapsoralen 20 was also synthesized by this method.

Utilisation of 13C N.M.R. Spectroscopy for the Identification of E- and Z-α,β-Unsaturated Esters, Ketones and Nitriles.

Measurement of 3JCO,H coupling constants provides an unambiguous procedure for the configurational analysis of substituted 2- and 3-arylpropenoic esters and of E- and Z-2-arylbut-2-en-1,4-dioates, even when only one of the isomers is available for analysis.An analogous procedure can also be used for the configurational analysis of 3-arylpropenonitriles and of 4-arylbut-3-en-2-ones.

High Pressure Experiments, XII. - Application of High Pressure on Wittig Reactions with Resonance Stabilized Ylides

At pressures of about 10 kbar the reaction of aldehydes with resonance stabilized ylides gets strongly accelerated.The yield of the trans-olefin is increased.