220765-18-4Relevant academic research and scientific papers
Stereoselective synthesis of chiral 2,3-cis-2-ethynylaziridines by base-mediated intramolecular amination of bromoallenes
Ohno, Hiroaki,Hamaguchi, Hisao,Tanaka, Tetsuaki
, p. 2269 - 2271 (2001)
(matrix presented) from (S,aS) 2,3-cis:trans = 79:21-89:11 (76-93% yield) from (S,aR) 2,3-cis:trans = 91:9-99:1 (50-99% yield) Novel stereoselective synthesis of 2,3-cis-2-ethynylaziridines from amino allenes is presented. While sodium hydride mediated intramolecular amination of (4S,aS)-4-alkyl-4-[N-(arylsulfonyl)amino]-1-bromobuta-1,2-dienes yields a mixture of 2,3-cis- and 2,3-trans-2-ethynylaziridines in which the cis-isomer predominates (79:21-89:11), the amination of (4S,aR)-isomers affords 2,3-cis-aziridines in excellent selectivities (91:9-100:0). Conversion of 2,3-trans-2-ethynylaziridines into the corresponding cis-isomers via a sequence of reactions (methanesulfonic acid mediated ring-opening reaction, bromination, and aziridination) is also described.
A highly cis-selective synthesis of 2-ethynylaziridines by intramolecular amination of chiral bromoallenes: Improvement of stereoselectivity based on the computational investigation
Ohno, Hiroaki,Ando, Kaori,Hamaguchi, Hisao,Takeoka, Yusuke,Tanaka, Tetsuaki
, p. 15255 - 15266 (2007/10/03)
The base-mediated intramolecular amination of bromoallenes having an axial chirality is described. The treatment of (4S,aR)-4-alkyl-4-[N-(arylsulfonyl)amino]-1-bromobuta-1,2-dienes with NaH in DMF affords 2,3-cis-2-ethynylaziridines in good to excellent s
Synthesis of allenes from allylic alcohol derivatives bearing a bromine atom using a palladium(0)/diethylzinc system
Ohno, Hiroaki,Miyamura, Kumiko,Tanaka, Tetsuaki,Oishi, Shinya,Toda, Ayako,Takemoto, Yoshiji,Fujii, Nobutaka,Ibuka, Toshiro
, p. 1359 - 1367 (2007/10/03)
A general and efficient synthesis of allenes using a palladium(0)/diethylzinc system is described. Treatment of mesylates or trichloroacetates of (E)- or (Z)-2-bromoalk-2-en-1-ols with diethylzinc in the presence of a catalytic amount of palladium(0) affords allenes bearing an aminoalkyl, alkyl, or aryl substituent(s) in good to high yields. No transfer of chirality from the stereogenic center carrying the mesyloxy group to the allene was observed.
Convenient syntheses of chiral 3-substituted 2-ethynylaziridines
Ohno, Hiroaki,Toda, Ayako,Takemoto, Yoshiji,Fujii, Nobutaka,Ibuka, Toshiro
, p. 2949 - 2962 (2007/10/03)
Two convenient methods for the synthesis of chiral 2-ethynylaziridines from natural α-amino acids are described. Sodium hydride-promoted aziridination of mesylates of 4-arylsulfonylamino-2-bromoalk-2-en-1-ols yields trans-2-(1-bromovinyl)aziridines in a highly stereoselective manner, and subsequent dehydrobromination of the aziridines by potassium tert-butoxide gives separable stereoisomeric mixtures of trans- and cis-2-ethynylaziridines in enantiomerically pure forms (>98% ee). Simple synthesis of 2-ethynylaziridines with high optical purities (91-98% ee) from chiral amino alcohols bearing an ethynyl group under Mitsunobu conditions is also presented. The Royal Society of Chemistry 1999.
A convenient synthesis of activated enantiomerically pure 2- ethynylaziridines
Ohno, Hiroaki,Toda, Ayako,Fujii, Nobutaka,Ibuka, Toshiro
, p. 3929 - 3933 (2007/10/03)
2,3-cis- and 2,3-trans-N-Arylsulfonyl-2-ethynylaziridines with high enantiomeric purity have been synthesized. N-Protected amino aldehydes synthesized from natural α-amino acids were successively treated with Ph3P=C(Br)CO2Me, DIBAL, MsCl-Et3N, NaH in DMSO, and tert-BuOK in THF to yield 2-ethynylaziridines in good to high yields.
