134731-67-2Relevant articles and documents
First example of an organocatalytic asymmetric Mannich reaction between aldimines of glycinates and sulphonyl imines
Wu, Lei,Li, Guangxun,He, Migu,Wang, Yingwei,Zhao, Gang,Tang, Zhuo
supporting information, p. 769 - 772 (2016/10/24)
The catalytic enantioselective Mannich-type reaction between glycinate Schiff base and imines has been one of the most efficient routes for accessing α,β-diamino acids. However, the glycinate Schiff bases used in the references were almost ketimines. Only
A new chiral Rh(II) catalyst for enantioselective [2 + 1]-cycloaddition. Mechanistic implications and applications
Lou, Yan,Horikawa, Manabu,Kloster, Robin A.,Hawryluk, Natalie A.,Corey
, p. 8916 - 8918 (2007/10/03)
A novel chiral Rh(II) catalyst (1) is introduced for the [2 + 1]-cycloaddition of ethyl diazoacetate to terminal acetylenes and olefins with high enantioselectivity. The catalyst 1 consists of one acetate bridging group and three mono-N-triflyldiphenylimidazoline-2-one bidentate ligands (DPTI) spanning the Rh(II)-Rh(II) metallic center in a structure that was determined by single-crystal X-ray diffraction analysis. A rational mechanism is advanced that provides a straightforward explanation for the enantioselectivity and absolute stereochemical course of the [2 + 1]-cycloaddition reactions. A key element in this explanation is the cleavage of one of the Rh-O bonds of the bridging acetate group in the intermediate Rh-carbene complex to form a new pentacoordinate Rh carbene complex (formally 1.5 valent Rh) that can undergo [2 + 2]-cycloaddition with the C-C π-bond of the acetylenic or olefinic substrate. Reductive elimination of the resulting adduct affords the cyclopropene or cyclopropane product. The C2-symmetry of the two DPTI ligands orthogonal to the bridging acetate also contributes to the high observed enantioselectivity and mechanistic clarity. The catalyst 1, which functions effectively at 0.5 mol %, can be recovered efficiently for reuse. Its ready availability, robustness, and effectiveness suggest it as a useful addition to the list of practical chiral Rh(II) catalysts for synthesis. Copyright
Synthesis of C2 symmetric 2,2′-bipyridyl imidazolidinone and oxazaborolidine derivatives
Ward, Robert S.,Branciard, Denis,Dignan, Rosemary A.,Pritchard, Martyn C.
, p. 157 - 170 (2007/10/03)
4,4′-Bis(bromomethyl)-2,2′-bipyridine reacts with (4R, 5R)-1-propanoyl-4,5-diphenylimidazolidinone to form a C2 symmetric chiral bipyridine derivative. Similarly reaction of 4,4′-bis(bromomethyl)-2,2′-bipyridine with an amino alcohol prepared from L-tyrosine affords a C2 symmetric diaminodiol. Treatment of the latter product with either borane or trimethylboroxine forms oxazaborolidines that have been used as catalysts in the asymmetric reduction of acetophenone. High enantiomeric excesses are obtained.
Catalytic oxidative carbonylation of primary and secondary α,ω-diamines to cyclic ureas
McCusker, Jennifer E.,Grasso, Cara A.,Main, Andrea D.,McEiwee-White, Lisa
, p. 961 - 964 (2008/02/09)
(matrix presented) Primary and secondary diamines can be catalytically carbonylated to cyclic ureas using W(CO)6 as the catalyst, I2 as the oxidant, and CO as the carbonyl source. Preparation of five-, six-, and seven-membered cyclic ureas from the diamines RNHCH2(CH2)nCH2NHR (n = 0-2; R = H, Me) and RNHCH2CH2NHR (R = Et, i-Pr, Bz) was achieved in moderate to good yields.
Synthesis of chiral oxazolidin-2-ones and imidazolidin-2-ones via DMAP- catalyzed isocyanation of amines with di-tert-butyl dicarbonate
Knoelker, Hans-Joachim,Braxmeier, Tobias
, p. 9407 - 9410 (2007/10/03)
Oxazolidin-2-ones and imidazolidin-2-ones are prepared under mild reaction conditions by DMAP-catalyzed isocyanation of 1,2-aminoalcohols and 1,2-diamines with di-tert-butyl dicarbonate and subsequent cyclization.
Stereocontrol in the reduction of 1,2-diimine with an oxazaborolidine catalyst. Highly stereoselective preparation of (R,R)-1,2-diphenylethylenediamine
Shimizu, Makoto,Kamei, Mie,Fujisawa, Tamotsu
, p. 8607 - 8610 (2007/10/02)
Highly enantioselective reduction of 1,2-bis(p-methoxyphenylimino)-1,2-diphenylethane was conducted even with 0.5 mol% of new oxazaborolidine derived from L-threonine and a stoichiometric amount of BH3·THF to give 1,2-diphenylethylenediamine derivative in excellent enantiomeric purity. The subsequent deprotection of nitrogen atoms afforded (R,R)-1,2-diphenylethylenediamine in enantiomerically pure form.
Highly Enantioselective Imino Pinacol Coupling Leading to the Synthesis of 1,2-Diphenylethylenediamine Derivatives
Shimizu, Makoto,Iida, Toyoshi,Fujisawa, Tamotsu
, p. 609 - 610 (2007/10/03)
Enantioselective imino pinacol coupling of p-anisylbenzalimine was promoted by the use of Zn-Cu couple in the presence of (+)-camphorsulfonic acid to give (R,R)-1,2-diphenylethylenediamine derivative in high enantiomeric purity.
New Chiral Auxiliary; 4,5-Diphenyl-1-methyl-2-imidazolidinone. Its Utility in Highly Enantioselective Aldol Reaction
Sankhavasi, Wongsiri,Yamamoto, Makoto,Kohmoto, Shigeo,Yamada, Kazutoshi
, p. 1425 - 1427 (2007/10/02)
The aldol reaction of the boron enolate bearing the titled chiral auxiliary proceeded with high face selectivity.
Bifunctional chiral auxiliaries 3: Synthesis of homochiral 1,3-diols via asymmetric aldol reactions of dialkylboron enolates of 1,3-dipropionyl-trans-4,5-diphenyl-imidazolidin-2-one and aldehydes
Davies,Mortlock
, p. 1001 - 1004 (2007/10/02)
Dibutylboron enolates derived from both racemic and homochiral 1,3-dipropionyl-trans-4,5-diphenylimidazolidin-2-one 3 react with aldehydes in highly diastereoselective dialdol reactions to give, after reductive cleavage of the acyl sidechain, substituted 1,3 diols.
