20614-90-8

Upstream product

• 186581-53-3 diazomethane 
• 59005-31-1 tert-Butylketen 
• 201230-82-2 carbon monoxide 
• 558-17-8 tert-Butyl iodide 
• 106-95-6 allyl bromide 
• 182755-64-2 3-tert-butyl-2,2-dichlorocyclobutanone 
• 558-37-2 tert-butylethylene 
• 76-02-8 trifluoroacetyl chloride 
• 20476-25-9 3-t-Butyl-cyclobutanol-⁽¹⁾ 

Downstream Products

• 13294-73-0 1-tert-butyl-4-methylenecyclohexane 
• 5581-94-2 3-tert-Butyl-cyclopentanone 
• 107912-94-7 trans-2-tert.-Butyl-cyclopropan-carbonsaeure-(1)-amid 
• 1019842-37-5 1-(1-benzyloxy-propa-1,2-dienyl)-3-tert-butyl-cyclobutanol 

Relevant academic research and scientific papers

Desymmetrization of Prochiral Cyclobutanones via Nitrogen Insertion: A Concise Route to Chiral γ-Lactams

Asymmetric access to γ-lactams is achieved via a cyclobutanone ring expansion using widely available (1S,2R)-1-amino-2-indanol for chiral induction. Mechanistic analysis of the key N,O-ketal rearrangement reveals a Curtin–Hammett scenario, which enables a downstream stereoinduction (up to 88:12 dr) and is corroborated by spectroscopic, crystallographic, and computational studies. In combination with an easy deprotection protocol, this operationally simple sequence allows the synthesis of a range of optically pure γ-lactams, including those bearing all-carbon quaternary stereocenters. In addition, the formal synthesis of drug molecules baclofen, brivaracetam, and pregabalin further demonstrates the synthetic utility and highlights the general applicability of the presented method.

Baeyer-Villiger Oxidation of Cyclobutanones with 10-Methylacridinium as an Efficient Organocatalyst

Baeyer-Villiger oxidation of cyclobutanones is achieved in current developed protocol with 10-methylacridinium perchlorate (AcrH +ClO4-) as a novel organocatalyst both with irradiation at room temperature and without irradiation at elevated temperature. Excellent yields of the corresponding lactones are obtained and the possible mechanism has been proposed.

Palladium-catalyzed, asymmetric Baeyer-Villiger oxidation of prochiral cyclobutanones with PHOX ligands

Described in this report is a general method for the conversion of prochiral 3-substituted cyclobutanones to enantioenriched γ-lactones through a palladium-catalyzed Baeyer-Villiger oxidation using phosphinooxazoline ligands in up to 99% yield and 81% ee. Lactones of enantiopurity ≥93% could be obtained through a single recrystallization step. Importantly, 3,3-disubtituted cyclobutanones produced enantioenriched lactones containing a β-quaternary center.

Palladium-catalyzed diastereo- and enantioselective Wagner-Meerwein shift: Control of absolute stereochemistry in the C-C bond migration event

Inducing absolute stereochemistry in Wagner-Meerwein shifts was examined in a ring expansion protocol. Initiated by generation of a π-allylpalladium intermediate by hydropalladation of allenes, the ring expansion of allenylcyclobutanol substrates proceeded with excellent diastereo- and enantioselectivities. The results demonstrate that, during the C-C bond migration process, our chiral catalysts can control the stereochemistry of both the π-allylpalladium intermediate and the corresponding migration bond. Moreover, the stereochemical outcome of the reaction can be rationalized very well with the working model of the chiral catalyst. The method provides an efficient way to synthesize highly substituted cyclopentanones with an α-chiral O-tertiary center which has various synthetic applications.

3-(2-Acylamino-1-Hydroxyethyl)-Morpholine Derivatives and Their Use as Bace Inhibitors

The present invention provides BACE inhibitors of Formula (I); methods for their use and preparation, and intermediates useful for their preparation.