122332-14-3

Upstream product

• 28557-00-8 phenylzinc chloride 
• 106-95-6 allyl bromide 
• 74-88-4 methyl iodide 
• 591-51-5 phenyllithium 
• 6566-38-7 cis-1,2-dihydroxy-1,2-dimethyl-1,2-dihydroacenaphthalene 
• 122-78-1 phenylacetaldehyde 
• 1097189-44-0 allyl(dimethyl)(2-phenylethanoyl)silane 
• 1097189-54-2 2-(allyldimethylsilyl)-2-benzyl-1,3-dithiane 
• 31593-52-9 2-benzyl-1,3-dithiane 
• 1730-25-2 allylmagnesium bromide 
• 107-37-9 allyltrichlorosilane 
• 108-22-5 Isopropenyl acetate 

Downstream Products

• 1150312-95-0 (4R)-5-phenylpentane-1,2,4-triol 
• 1351823-05-6 (S)-4-(tert-butoxycarbonyloxy)-5-phenylpent-1-ene 
• 1351823-03-4 (S)-4-(tert-butyldimethylsiloxy)-5-phenylpent-1-ene 
• 1351823-10-3 (S)-4-(tert-butyldiphenylsiloxy)-5-phenylpent-1-ene 
• 1351823-09-0 (2R,4R)-4-(tert-butyldiphenylsiloxy)-5-phenylpentane-1,2-diol 
• 1351823-11-4 (R)-2-(tert-butyldiphenylsiloxy)-1-(oxiran-2-yl)-3-phenylpropane 
• 1351823-04-5 (2R,4R)-4-(tert-butyldimethylsiloxy)-5-phenylpentane-1,2-diol 
• 1351823-02-3 (2R,4R)-4-(tert-butyldimethylsiloxy)-5-phenylpentane-1,2-diol 
• 1351823-06-7 (4R,6R)-4-benzyl-6-(iodomethyl)-1,3-dioxan-2-one 
• 1351823-07-8 (R)-1-[(R)-oxiran-2-yl]-3-phenylpropan-2-ol 
• 1351823-08-9 (R)-2-(tert-butyldiphenylsiloxy)-1-[(R)-oxiran-2-yl]-3-phenyl-propane 
• 203243-30-5 3-hydroxy-5-phenylmethyl-(3R,5R)-tetrahydrofuran-2-one 
• 1374151-64-0 2-benzyl-4-hydroxy-1-oxa-7-azacyclotetradecane-6,14-dione 
• 1374151-65-1 C₁₉H₂₉NO₅ 

Relevant academic research and scientific papers

An evolutionary model encompassing substrate specificity and reactivity of type i polyketide synthase thioesterases

Bacterial polyketides are a rich source of chemical diversity and pharmaceutical agents. Understanding the biochemical basis for their biosynthesis and the evolutionary driving force leading to this diversity is essential to take advantage of the enzymes as biocatalysts and to access new chemical diversity for drug discovery. Biochemical characterization of the thioesterase (TE) responsible for 6-deoxyerythronolide macrocyclization shows that a small, evolutionarily accessible change to the substrate can increase the chemical diversity of products, including macrodiolide formation. We propose an evolutionary model in which TEs are by nature non-selective for the type of chemistry they catalyze, producing a range of metabolites. As one metabolite becomes essential for improving fitness in a particular environment, the TE evolves to enrich for that corresponding reactivity. This hypothesis is supported by our phylogenetic analysis, showing convergent evolution of macrodiolide-forming TEs.

Enantiomerically Enriched α-Borylzinc Reagents by Nickel-Catalyzed Carbozincation of Vinylboronic Esters

In this paper is described a synthesis of enantiomerically enriched, configurationally stable organozinc reagents by catalytic enantioselective carbozincation of a vinylboronic ester. This process furnishes enantiomerically enriched α-borylzinc intermediates that are shown to undergo stereospecific reactions, producing enantioenriched secondary boronic ester products. The properties of the intermediate α-borylzinc reagent are probed and the synthetic utility of the products is demonstrated by application to the synthesis of (-)-aphanorphine and (-)-enterolactone.

Enantioselective 1,2-Anionotropic Rearrangement of Acylsilane through a Bisguanidinium Silicate Ion Pair

Highly enantioselective bisguanidinium-catalyzed tandem rearrangements of acylsilanes are reported. The acylsilanes were activated via an addition of fluoride on the silicon to form a penta-coordinate anionic silicate intermediate. The silicate then underwent alkyl or aryl group migration from the silicon atom to the neighboring carbonyl carbon atom (1,2-anionotropic rearrangement), followed by [1,2]-Brook rearrangement to provide the secondary alcohols in high yields with excellent enantioselectivities (up to 95% ee). The isolation of an α-silylcarbinol intermediate as well as DFT calculations revealed that the 1,2-anionotropic rearrangement occurred via a bisguanidinium silicate ion pair, which is the stereodetermining step. The chiral center formed is then retained without inversion through the subsequent [1,2]-Brook rearrangement. Crotyl acylsilanes were smoothly transformed into homoallylic linear crotyl alcohols with retention of E/Z geometry, and no branched alcohols were detected. This clearly suggested that the 1,2-anionotropic rearrangement occurred through a three-membered instead of a five-membered transition state.

Asymmetric Synthesis of Borylalkanes via Copper-Catalyzed Enantioselective Hydroallylation

An efficient synthetic method for preparing enantioenriched secondary borylalkanes has been achieved through a copper-catalyzed regio- and enantioselective hydroallylation of alkenyl boronates and boramides employing hydrosilanes and allylic phosphates. In the presence of a copper catalyst with a chiral Walphos ligand, a range of alkenylboron compounds with an aryl, heteroaryl, or alkyl substituent produced secondary homoallylic alkylboron compounds in good yields and with high enantioselectivities up to 99% ee. The utility of the resulting alkylboronates was demonstrated in an efficient synthesis of (S)-massoialactone.

Towards a characterization of the structural determinants of specificity in the macrocyclizing thioesterase for deoxyerythronolide B biosynthesis

Type I polyketide synthases (PKSs) are giant multidomain proteins that synthesize many therapeutics and other natural products. The synthesis proceeds by a thiotemplate mechanism whereby intermediates are covalently attached to the PKS. The release of the final polyketide is catalyzed by the terminal thioesterase (TE) domain through hydrolysis, transesterification, or macrocyclization. The PKS 6-deoxyerythronolide B synthase (DEBS) produces the 14-membered macrolide core of the clinically important antibiotic erythromycin. The TE domain of DEBS (DEBS TE) has well-established, empirically-defined specificities for hydrolysis or macrocyclization of native and modified substrates. We present efforts towards understanding the structural basis for the specificity of the thioesterase reaction in DEBS TE using a set of novel diphenyl alkylphosphonates, which mimic substrates that are specifically cyclized or hydrolyzed by DEBS TE. We have determined structures of a new construct of DEBS TE alone at 1.7 ?, and DEBS TE bound with a simple allylphosphonate at 2.1 ? resolution. Other, more complex diphenyl alkylphosphonates inhibit DEBS TE, but we were unable to visualize these faithful cyclization analogs in complex with DEBS TE. This work represents a first step towards using DEBS TE complexed with sophisticated substrate analogs to decipher the specificity determinants in this important reaction.

Oxazoline derivatives tagged with tosylated amino acids as recyclable organocatalysts for enantioselective allylation of aldehydes

A series of amino acid-based oxazoline compounds have been prepared and successfully applied to the enantioselective allylation reaction of aldehydes. The fine-tuning of the structure of the oxazolines led to (S,S)-4 as an efficient organocatalyst which gave homoallyl alcohols in good yield (up to 90%) and excellent ee (up to 99%) for a wide range of substrates including aromatic, hetero-aromatic and α,β-unsaturated aldehydes. The chiral organocatalyst was synthesized in three easy steps with an overall 88% yield and successfully recycled for up to three cycles. On the basis of the experimental observations and NMR studies, a probable mechanism was proposed for this reaction.

Dynamic kinetic resolution of homoallylic alcohols: Application to the synthesis of enantiomerically pure 5,6-dihydropyran-2-ones and δ-lactones

Dynamic kinetic resolution of various homoallylic alcohols with the use of Candida antarctica lipase B and ruthenium catalyst 2 afforded homoallylic acetates in high yields and with high enantioselectivity. These enantiopure acetates were further transfor

6-Deoxyerythronolide B synthase thioesterase-catalyzed macrocyclization is highly stereoselective

Macrocyclic polyketide natural products are an indispensable source of therapeutic agents. The final stage of their biosynthesis, macrocyclization, is catalyzed regio- and stereoselectively by a thioesterase. A panel of substrates were synthesized to test their specificity for macrocyclization by the erythromycin polyketide synthase TE (DEBS TE) in vitro. It was shown that DEBS TE is highly stereospecific, successfully macrocyclizing a 14-member ring substrate with an R configured O-nucleophile, and highly regioselective, generating exclusively the 14-member lactone over the 12-member lactone.

Stereoselective synthesis of cytotoxic marine metabolite harzialactone a by three different routes

The cytotoxic marine metabolite harzialactone A has been synthesized stereoselectively starting from phenylacetaldehyde through three different routes. The key steps were: in the first approach Sharpless asymmetric dihydroxylation, in the second approach

Chemoenzymatic asymmetric synthesis of harzia lactone A stereomers

A facile chemoenzymatic synthesis of the harzia lactone A enantiomers was developed. A lipase-catalyzed acylation and an enantio-controlled substrate and reagent-controlled Sharpless' asymmetric dihydroxylation are the key features of the synthesis.