4397-23-3Relevant articles and documents
BORON-BASED CYCLOADDITION CATALYSTS AND METHODS FOR THE PRODUCTION OF BIO-BASED TEREPHTHALIC ACID, ISOPHTHALIC ACID AND POLY (ETHYLENE TEREPHTHALATE)
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Paragraph 00171; 00187, (2017/04/11)
Methods for producing cycloaddition products comprising: reacting a diene with a dienophile in the presence of one or more boron-based catalysts of Formula I or Formula II are provided. In particular, the methods can be used to prepare 4-methyl-3-cyclohexene- 1-carboxylic acid and 3-methyl-3-cyclohexene-l-carboxylic acid, including bio-based versions thereof. The cycloaddition products can be advantageously used in the production of terephthalic acid and isophthalic acid, and ultimately, poly(ethylene terephthalate), and bio-based versions thereof. Formula I Formula II
SuperQuat 5,5-dimethyl-4-iso-propyloxazolidin-2-one as a mimic of Evans 4-tert-butyloxazolidin-2-one
Bull, Steven D.,Davies, Stephen G.,Garner, A. Christopher,Kruchinin, Dennis,Key, Min-Suk,Roberts, Paul M.,Savory, Edward D.,Smith, Andrew D.,Thomson, James E.
, p. 2945 - 2964 (2008/02/09)
The incorporation of a gem-dimethyl group at the 5-position of a chiral oxazolidinone biases the conformation of the adjacent C(4)-stereodirecting group such that the gem-dimethyl-4-iso-propyl combination mimics a C(4)-tert-butyl group, providing higher levels of stereocontrol than a simple 4-iso-propyloxazolidinone. The generality of this principle is demonstrated with applications in stereoselective enolate alkylations, kinetic resolutions, Diels-Alder cycloadditions and Pd-catalysed asymmetric acetalisation reactions. The Royal Society of Chemistry 2006.
DMAP-promoted racemization-free deacylation of carboxthioimide adducts: Carboxthioimide as a versatile carboxy protecting group
Su, Dah-Wei,Wang, Ying-Chuan,Yan, Tu-Hsin
, p. 545 - 546 (2007/10/03)
The DMAP-promoted deacylation of carboxthioimide adducts can be directed to form either acid or various ester protecting groups with no detectable levels of epimerization.