340169-21-3

Upstream product

• 588-72-7 [(E)-2-bromoethenyl]benzene 
• 927-74-2 3-Butyn-1-ol 
• 118576-27-5 (E)-5-phenyl-4,6-heptadienoic acid methyl ester 
• 14371-10-9 (E)-3-phenylpropenal 
• 51860-45-8 3-hydroxypropyltriphenylphosphonium bromide 
• 105952-21-4 ethyl 6-phenyl-3(E),5(E)-hexadienoate 

Downstream Products

• 372076-32-9 6-phenyl-3(E),5(E)-hexadienyl azidoformate 

Relevant academic research and scientific papers

Direct Formic Acid Mediated Z-Selective Reductive Coupling of Dienes and Aldehydes

Methods for the addition of unsaturated nucleophiles to carbonyls to generate Z-olefin products remain rare and often require either alkyl borane or zinc reductants, limiting their utility. Demonstrated here is that formic acid mediates the Rh-catalyzed,

Tandem Wittig-intramolecular Diels-Alder cycloaddition of ester-tethered 1,3,9-decatrienes under microwave heating

Intramolecular Diels-Alder (IMDA) cycloaddition of the ester-tethered 1,3,9,-decatrienes possessing a carbonyl substituent at C10 has been investigated under controlled microwave heating (MeCN, 180 °C) to afford a variety of 3,4,4a,7,8,8a-hexahydroisochromen-1-ones in 53-89% yields and in 64:36-79:21 ratios for the cis and trans isomers. Under the same microwave heating conditions, a tandem Wittig-IMDA cycloaddition, starting from the α-bromoacetates of 3,5-hexadien-1-ols and glyoxalate/phenylglyoxal hydrates in the presence of PPh3 and 2,6-lutidine, has been demonstrated, furnishing 3,4,4a,7,8,8a-hexahydroisochromen-1-one adducts in 73-91% yields in favor of the cis isomers. During this tandem process, three consecutive carbon-carbon bonds in the end products were efficiently formed with the aid of microwave irradiation within short reaction times.

Stille reactions catalytic in tin: A "Sn-F" route for intermolecular and intramolecular couplings

(Chemical Equation Presented) Polymethylhydrosiloxane (PMHS) made hypercoordinate by KF(aq) allows Me3SnH to be recycled during a Pd(0)-catalyzed hydrostannation/Stille cascade. Starting with a variety of alkynes, in situ vinyltin formation is followed by Stille reaction with aryl, styryl, benzyl, or vinyl electrophiles present in the reaction mixture. Both inter- and intramolecular versions of the process are possible with tin loads of approximately 6 mol %. Regeneration of the organotin hydride is believed to proceed through a Me3SnF intermediate. Given the aggregated nature of organotin fluorides and the ability to use these organotins in substoichiometric quantities, the hazards and purification problems associated with the removal of organotin wastes from reaction mixtures are minimized.

Stille couplings catalytic in tin: The "Sn-O" approach

A one-pot tandem Pd-catalyzed hydrostannylation/Stille coupling protocol for the stereoselective generation of vinyltins and their subsequent union, employing only catalytic amounts of tin, is described. By recycling the organotin halide Stille byproduct back to organotin hydride, a hydrostannylation/cross-coupling sequence can be carried out with catalytic amounts of tin. Such a process is most effective with Me3SnCl serving as the tin source. This protocol allows a 94% reduction of the tin requirement, while maintaining good yields (up to 90%) for a variety of Stille products. Furthermore, since one cycle requires the tin to undergo at least four transformations, each moiety of trialkyltin is experiencing a minimum of 60 reactions over the course of the hydrostannylation/Stille, sequence.

Synthesis and mechanistic study of fused 2-pyrrolines via thermolysis of 6-substituted-3,5-hexadienyl azidoformates

Thermolysis of 3,5-hexadienyl azidoformates at 300 °C, 0.05 Torr, led to a fused 2-pyrroline regiospecifically, regardless of the configuration E or Z between the C-3 and C-4 double bond. Thermolysis of 6-substituted-3,5(E)-hexadienyl azidoformates yielded a kinetically controlled 2-pyrroline with cis configuration between H-1 and H-8a whereas 6-substituted-3,5(Z)-hexadienyl azidoformates produced a cis and trans mixture. The mechanism was proposed as the loss of nitrogen to form an acyl nitrene, then addition to a double bond to produce an aziridine. Finally the cleavage of the C-C bond generated a vinylazomethine ylide followed by recyclization to a fused 2-pyrroline.