51479-71-1

Upstream product

• 104-54-1 3-Phenylpropenol 
• 545-06-2 trichloroacetonitrile 
• 4407-36-7 (2E)-3-phenyl-2-propen-1-ol 

Downstream Products

• 250234-74-3 trimethyl-[1-(1-phenyl-allyloxy)-allyl]-silane 
• 911466-04-1 (E)-(1-(cinnamyloxy)allyl)trimethylsilane 
• 4393-21-9 1-(phenyl)allylamine 
• 138313-55-0 N-(1-Phenyl-2-propenyl)formamid 
• 138313-60-7 1-Phenyl-1-propenylisocyanid 
• 91230-12-5 (1-phenyl-allyl)-carbamic acid tert-butyl ester 
• 374725-03-8 tert-butyl (-formyl-1-phenylethyl)carbamate 

Relevant academic research and scientific papers

Synthesis of Rovafovir Etalafenamide (Part III): Evolution of the Synthetic Process to the Phosphonamidate Fragment

Phosphonamidate 1 is a key fragment in the assembly of rovafovir etalafenamide, a novel nucleotide reverse transcriptase inhibitor under development at Gilead Sciences for the treatment of HIV infection. An early manufacturing route, relying on simulated moving bed (SMB) chromatography for the separation of phosphorus diastereomers, was executed on scale to produce multiple batches of 1. However, developing alternative synthetic conditions became desirable in consideration of the high production cost, long lead time, and high process mass intensity (PMI) associated with SMB. Several strategies to improve these factors are described herein, including epimerization and recycling of the undesired (R)-phosphorus diastereomer, design of stereoselective approaches to establish the desired (S)-configuration at phosphorus, and identification of conditions or derivatives to allow for selective crystallization. Ultimately, a second-generation route to 1 was developed and demonstrated on scale. The new route achieves the separation of phosphorus diastereomers by means of selective crystallization, does not require SMB, and offers lower PMI, cost, and lead time.

A Simple Method for the Preparation of Stainless and Highly Pure Trichloroacetimidates

We describe a method for obtaining various allylic, benzylic, and glucosyl 2,2,2-trichloroacetimidates (TCAIs) as stainless liquids or solids at the crude stage. The general synthetic method for the preparation of TCAIs often leads to stained products, and further purification of crude TCAIs causes decomposition due to their instability. In the described method, we use a solvent that barely dissolves the reactant, providing stainless and sufficiently pure TCAIs without requiring a purification step. Furthermore, the reaction mixture is turbid at the beginning and clear at the end, allowing us to monitor the progress of the reaction visually.

Determination of the Absolute Configuration of (S)-N-(1-Aryl-allyl)-3,5-dinitrobenzamides and Their Elution Order on Brush-Type Chiral Stationary Phases

A series of ten enantiomerically pure (S)-N-(1-aryl-allyl)-3,5-dinitrobenzamides (S-DNBs) was prepared using enzymatic resolution and chiral chromatography. Enzymatic resolution of corresponding 1-aryl-allylamines using Candida antarctica lipase B (CaLB) was efficient for amines with no steric hindrance near the stereogenic center and S-DNB amides were prepared by acylation of the obtained S-amine. When steric effects interrupted enzymatic resolution, racemic DNB amides were resolved using a brush-type chiral column (CSP-A) developed in our laboratory. Previously reported behavior of CaLB in kinetic resolution of amines was considered a starting point for the determination of absolute configuration (AC). The AC of prepared S-DNB amides was anticipated using the elution order of prepared DNB amides on CSP-A and commercial Whelk-O1 columns and comparison with DNB amides obtained after acylation of (S)-amines. The comparison between experimental electronic circular dichroism (ECD) spectra with those obtained by conformational analysis and ECD calculations of representative compounds allowed us to verify the AC of prepared DNB amides.

A short synthesis of pyridines from deprotonated α-aminonitriles by an alkylation/RCM sequence

α-Aminonitriles can serve as versatile key precursors for the synthesis of nitrogen containing heterocycles. After unsuccessful trials involving the [1,2]-Stevens rearrangement of nitrile-stabilized ammonium ylides, we herein report a simple three-step synthesis of substituted pyridines based on an alkylation/ring-closing metathesis/aromatization sequence.

Palladium-catalyzed anti-markovnikov oxidation of allylic amides to protected β-amino aldehydes

A general method for the preparation of N-protected β-amino aldehydes from allylic amines or linear allylic alcohols is described. Here the Pd(II)-catalyzed oxidation of N-protected allylic amines with benzoquinone is achieved in tBuOH under ambient conditions with excellent selectivity toward the anti-Markovnikov aldehyde products and full retention of configuration at the allylic carbon. The method shows a wide substrate scope and is tolerant of a range of protecting groups. Furthermore, β-amino aldehydes can be obtained directly from protected allylic alcohols via palladium-catalyzed autotandem reactions, and the application of this method to the synthesis of β-peptide aldehydes is described. From a mechanistic perspective, we demonstrate that tBuOH acts as a nucleophile in the reaction and that the initially formed tert-butyl ether undergoes spontaneous loss of isobutene to yield the aldehyde product. Furthermore, tBuOH can be used stoichiometrically, thereby broadening the solvent scope of the reaction. Primary and secondary alcohols do not undergo elimination, allowing the isolation of acetals, which subsequently can be hydrolyzed to their corresponding aldehyde products.

Effect of halogenation reagents on halocyclization and Overman rearrangement of allylic trichloroacetimidates

Electrophilic halogen can promote either halocyclization or Overman rearrangement of allylic trichloroacetimidates. We found that the chemoselectivity was dependent on the nature of the halogenation reagents for primary allylic trichloroacetimidates. A one-pot procedure was developed for the preparation of allylic trichloroacetamides directly from allylic alcohols at room temperature.

A New α-Amino Acid Synthesis via an Acetimidate Rearrangement

A new efficient synthesis of α-amino acids from allyl alcohol derivatives via an acetimidate rearrangement has been developed.