13019-35-7

Upstream product

• 201230-82-2 carbon monoxide 
• 207129-88-2 (4-(benzyloxy)but-1-yn-1-yl)benzene 
• 13019-38-0 3-bromo-3-phenyl-tetrahydro-pyran-2-one 
• 13019-37-9 α-phenyl δ-valerolactone 
• 10229-11-5 4-phenyl-but-3-yn-1-ol 
• 937-58-6 (3E)-4-phenyl-3-buten-1-ol 
• 192064-78-1 (Z)-4-iodo-4-phenyl-3-buten-1-ol 

Downstream Products

• 1193511-33-9 (Z)-2-phenylpent-2-ene-1,5-diol 
• 102397-26-2 3-phenyl-2H-pyran-2-one 

Relevant academic research and scientific papers

Development of a method for the synthesis of α-substituted α,β- unsaturated lactones based on stille-type Pd-catalyzed carbonylation of (Z)- ω-iodoalkenols. An efficient and selective synthesis of (+)-hamabiwalactone B

Pd-Catalyzed carbonylative lactonization of (Z)-ω-iodoalkenols can be applied to synthesize α/β-unsaturated lactones containing an alkenyl or alkynyl substituent in the α position, providing a generally superior alternative to recently developed methods involving Pd-catalyzed α- substitution of α-stannyl esters, as exemplified by a highly expeditious synthesis of (+)-hamabiwalactone B.

Electrochemically driven desaturation of carbonyl compounds

Electrochemical techniques have long been heralded for their innate sustainability as efficient methods to achieve redox reactions. Carbonyl desaturation, as a fundamental organic oxidation, is an oft-employed transformation to unlock adjacent reactivity through the formal removal of two hydrogen atoms. To date, the most reliable methods to achieve this seemingly trivial reaction rely on transition metals (Pd or Cu) or stoichiometric reagents based on I, Br, Se or S. Here we report an operationally simple pathway to access such structures from enol silanes and phosphates using electrons as the primary reagent. This electrochemically driven desaturation exhibits a broad scope across an array of carbonyl derivatives, is easily scalable (1–100 g) and can be predictably implemented into synthetic pathways using experimentally or computationally derived NMR shifts. Systematic comparisons to state-of-the-art techniques reveal that this method can uniquely desaturate a wide array of carbonyl groups. Mechanistic interrogation suggests a radical-based reaction pathway. [Figure not available: see fulltext.]

Accessing non-natural reactivity by irradiating nicotinamide-dependent enzymes with light

Enzymes are ideal for use in asymmetric catalysis by the chemical industry, because their chemical compositions can be tailored to a specific substrate and selectivity pattern while providing efficiencies and selectivities that surpass those of classical synthetic methods. However, enzymes are limited to reactions that are found in nature and, as such, facilitate fewer types of transformation than do other forms of catalysis. Thus, a longstanding challenge in the field of biologically mediated catalysis has been to develop enzymes with new catalytic functions. Here we describe a method for achieving catalytic promiscuity that uses the photoexcited state of nicotinamide co-factors (molecules that assist enzyme-mediated catalysis). Under irradiation with visible light, the nicotinamide-dependent enzyme known as ketoreductase can be transformed from a carbonyl reductase into an initiator of radical species and a chiral source of hydrogen atoms. We demonstrate this new reactivity through a highly enantioselective radical dehalogenation of lactones - a challenging transformation for small-molecule catalysts. Mechanistic experiments support the theory that a radical species acts as an intermediate in this reaction, with NADH and NADPH (the reduced forms of nicotinamide adenine nucleotide and nicotinamide adenine dinucleotide phosphate, respectively) serving as both a photoreductant and the source of hydrogen atoms. To our knowledge, this method represents the first example of photo-induced enzyme promiscuity, and highlights the potential for accessing new reactivity from existing enzymes simply by using the excited states of common biological co-factors. This represents a departure from existing light-driven biocatalytic techniques, which are typically explored in the context of co-factor regeneration.

A convenient synthesis of 3-aryl-δ-lactones

Various (±)-3-aryl-δ-lactones have been prepared from the corresponding arylacetic acids. The lithium dianion of the acid is alkylated with 1-bromo-3-chloropropane and the unpurified product is cyclized with DBU in typically ca. 80% yield over both steps.

A concise synthesis of (S)-(+)-5,6-2H-pyran-2-one via hydrozirconation- carbonylation-demetallation of O-benzyl (S)-(-)-4-pentyn-2-ol

A simple synthetic approach to α,β-unsaturated δ-lactones has been devised from the hydrozirconation of O-protected homopropargyl alcohols followed by carbonylation and quenching with iodine. The synthesis of (S)- (+)-5,6-2H-pyran-2-one (parasorbic acid)