A New and Improved Preparation of Acyclic .sigma.-Dialkoxyphosphoranes

Mathieu-Pelta, Isabel; Evans, Slayton A.

doi:10.1021/jo00087a047

Cited by 10 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This species places the carboxylic acid R-subsituent (alkyl, aryl) in proximity to 1 of the 3 phenyl groups in the proposed trigonal–bipyramidal intermediate 14 . X-ray crystallographic studies of disubstituted triphenylphosphoranes25,38 show that the 3 phenyl groups are canted with respect to one another. If the esterification reaction proceeds through 14 then the phenyl R-substituent in 10 is likely to undergo an adverse steric interaction with 1 of the 3 phenyl groups in the triphenylphosphorane compared with the aliphatic R-substituent in 2 .…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Triphenylphosphine dibromide: a simple one-pot esterification reagent

Salomé

Kohn

2009

Tetrahedron

View full text Add to dashboard Cite

We report a one-pot, expedient protocol for the conversion of carboxylic acids to their esters using excess triphenylphosphine dibromide, base, and the alcohol. The reaction gave the esterified product in moderate-to-high yields (30-95%). For chiral acids, the reaction proceeded with little or no racemization. Use of a chiral alcohol in this transformation gave the ester with retention of configuration of the stereogenic center. Information is presented indicating that esterification proceeds through the intermediate generation of an acyloxyalkoxyphosphorane and where steric interactions play an important role in the energetics of the reaction.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Reagent 1 is commercially available and can be prepared from triphenylphosphine and Br 2 in near–quantitative yields 25. The method relies on in situ conversion of 1 to an alkoxyphosphorane, which serves as the esterification agent.…”

Section: Discussionmentioning

confidence: 99%

Triphenylphosphine dibromide: a simple one-pot esterification reagent

Salomé

Kohn

2009

Tetrahedron

View full text Add to dashboard Cite

show abstract

“…In 1989, van Boom reported a solution to this problem 9. Utilizing Evans’ one-step cyclodehydration conversion of 2-amino alcohols to aziridines with diethoxytriphenylphosphorane (DTPP),10 treatment of 10 with DTPP provided the unsubstituted (2 S )-aziridine-2-carboxylates 11 . Thus, we treated d -serine methyl ester ( 12 ) with DTTP to give the desired methyl (2 R )-aziridine-2-carboxylate ( 13a ) along with the corresponding ethyl ester 13b in 50−60% total yield (Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

“…The route takes advantage of a rapid and short synthesis of 14 using readily available DTPP 10. Key to the preparation of these compounds is the BF 3 ·Et 2 O ring opening of aziridine 14 with alcohols and phenol.…”

Section: Discussionmentioning

confidence: 99%

Synthesis and anticonvulsant activities of N-benzyl (2R)-2-acetamido-3-oxysubstituted propionamide derivatives

Morieux

Stables

Kohn

2008

Bioorganic & Medicinal Chemistry

View full text Add to dashboard Cite

Lacosamide has been submitted for regulatory approval in the United States and Europe for the treatment of epilepsy. Previous synthetic methods did not permit the elaboration of the structureactivity relationship (SAR) for the 3-oxy site in lacosamide. We report an expedient five-step stereospecific synthesis for N-benzyl (2R)-2-acetamido-3-oxysubstituted propionamide analogs beginning with D-serine methyl ester. The procedure incorporated alkyl (e.g. methyl, primary, secondary, and tertiary) and aryl groups at this position. The SAR for the 3-oxy site showed maximal activity in animal seizure models for small 3-alkoxy substituents.

show abstract

“…It also finds application in the synthesis of Triphenylphosphine dibromide is a colorless crystalline hygroscopic solid (mp 235°C) that is readily prepared before use by addition of an equimolar amount of bromine to triphenylphosphine in anhydrous diethyl ether at 0°C (Scheme 1). 4 It is a molecular compound in the solid state, but ionises in dichloromethane to form [Ph 3 PBr] + Br -. Horner and co-workers 1 demonstrated the application of triphenylphosphine dibromide for the conversion of alcohols and phenols into bromides.…”

Section: Introductionmentioning

confidence: 99%

Triphenylphosphine Dibromide

2010

Synlett

View full text Add to dashboard Cite

This feature focuses on a reagent chosen by a postgraduate, highlighting the uses and preparation of the reagent in current research Triphenylphosphine Dibromide Compiled by GarimaGarima was born in Allahabad, Uttar Pradesh, India. She obtained her B.Sc. (1999) and M.Sc. ( 2001) degrees in Organic Chemistry from the Allahabad University, Uttar Pradesh, India. After serving as a guest lecture in chemistry for five years (2003)(2004)(2005)(2006)(2007)(2008) at the C.M.P. Degree College, Allahabad, she joined the research group of Prof. L. D. S. Yadav for her doctoral studies in April 2008 as a JRF of CSIR. Her research interests focus on the development of green synthetic routes to novel molecular structures for applications in functional materials.

show abstract

A New and Improved Preparation of Acyclic .sigma.-Dialkoxyphosphoranes

Cited by 10 publications

References 0 publications

Triphenylphosphine dibromide: a simple one-pot esterification reagent

Triphenylphosphine dibromide: a simple one-pot esterification reagent

Synthesis and anticonvulsant activities of N-benzyl (2R)-2-acetamido-3-oxysubstituted propionamide derivatives

Triphenylphosphine Dibromide

Contact Info

Product

Resources

About