Single Route to Chiral <i>s</i><i>yn</i>- and <i>a</i><i>nti</i>-2-Amino-1,2-diphenylethanols via a New Stereodivergent Opening of <i>trans</i>-1,2-Diphenyloxirane
Oxiranyl ringopening of trans-stilbene oxide gave rise to anti- or syn-2-bromo-1,2-diphenylethanols, using either MgBr(2).Et(2)O or MgBr(2).Et(2)O, NaBr, and KBr with Amberlyst 15, respectively. Starting from optically pure (R,R)-trans-stilbeneoxide, (1R,2R)- and (1R,2S)-2-amino-1,2-diphenylethanols were obtained in high yield and ee.
Umsetzung von 2-Azidoalkoholen mit Trialkylphosphiten Bildung von Aziridinen und Amidophosphorsäureesten<i>via</i>Imidophosphorsäureester und 1,3,2λ<sup>5</sup>-Oxazaphospholidine
作者:Armin Willeit、Ernst Peter Müller、Paul Peringer
DOI:10.1002/hlca.19830660812
日期:1983.12.14
Reaction of 2-Azidoalcohols with Trialkylphosphites. Formation of Aziridines and Amidophosphates via Imidophosphates and 1,3,2λ5-Oxazaphospholidines
Diphenylphosphinoyl chloride as a chlorinating agent ? the selective double activation of 1,2-diols
作者:David J. Fox、Daniel Sejer Pedersen、Asger B. Petersen、Stuart Warren
DOI:10.1039/b606881b
日期:——
Treatment of 1,2-diols with diphenylphosphinoyl chloride in pyridine produces beta-chloroethyl phosphinates which react with complete control of stereochemistry to give epoxides and azido-alcohols, useful intermediates in cyclopropane synthesis.
Unusual C−C bondcleavage of 2,3-diaryl aziridines took place to afford secondary amines by formal dihydrogenation and hydrocyanation. Formal dehydrogenation was performed by electrocyclic ring opening of N-Li or N-Na aziridines to azaallyl anions followed by reduction with NaBH4. Formal hydrocyanation was realized by treating azaallyl anions with Me3SiCN.
Highly regio and chemoselective ring opening of epoxides with trimethylsilyl azide in the presence of aluminium isopropoxide and titanium isopropoxide
作者:Kun I. Sutowardoyo、Mohamed Emziane、Paul Lhoste、Denis Sinou
DOI:10.1016/s0040-4020(01)86420-6
日期:1991.1
The ring-opening of functionalized epoxides with trimethylsilyl azide in the presence of a catalytic amount of Ti(O-i-Pr)4 or Al(O-i-Pr)3 is described. The reaction is stereospecific and highly regiospecific, leading generally to the formation of the carbon-azido bond on the less substituted carbon. The mechanism of this reaction is also discussed.