otto
(Hive Bee)
10-18-02 11:11
No 369990
       concerning: aziridines
(Rated as: excellent) 		    

dear bees,

concerning aziridines otto has found some nice recent refs. they all claim to make valuable aziridines from easy to get Chloramine T.

first is JACS 1998, 120, 6844-6845 "bromine-catalyzed aziridination of olefins"
then Tetrahedron 54 (1998) 13485-13494 "iodine-catalyzed aziridination of alkenes using chloramine-T as a nitrogen source"
and finally J. Chem. Soc., Perkin Trans. I, 2001, 3186-3188 "novel organic-solvent-free aziridination of olefins: chloramine-t-I2 system under phase-transfer catalysis conditions"

can`t get better than the last one: no organic solvent, just alkene, water, Chloramine-T, and iodine and PTC as catalyst. the article is freely accessible at www.rsc.org.

so otto proposes a novel route to tma-2. take asarone and make the n-tosylaziridine according to one of those procs. the aziridine gives upon reductive cleavage (may be CTH?) the N-tosylamide of tma-2. last step is then deprotection. how difficult or easy that may be, otto has no idea. however here is one ref if one wants to remove the tosyl group right away from the aziridine.

it`s JOC 1998, 68, 9455-9461 "deprotection of sulfonyl aziridines"

otto 		 
 
 
 
    otto
(Hive Bee)
10-18-02 12:03
No 369999
       CTH, yes     

otto came to read the thread "The most interesting CTH reaction ever documented?" of Regis. the needed O-acyl-phenylpropanolamines can easily be prepared from aziridines and acetic acid (no acetic anhydride!). look at

 J. Korean Chem. Soc., 1969, 229-232 "ring-opening reaction of 2,2-gem-diphenylqziridine"

otto

p.s. this article is freely available from the homepage of korean chem soc. 		 
 
 
 
    Rhodium
(Chief Bee)
10-18-02 17:06
No 370075
       I have posted details on how to deprotect using ..     

I have posted details on how to deprotect using HBr/Phenol in Post 339848 (Rhodium: "Sulfonamide cleavage", Novel Discourse) 		 
 
 
 
    Rhodium
(Chief Bee)
10-01-03 13:05
No 462123
       Mg/MeOH Deprotection of N-Tosyl-Aziridines     

The correct reference for the JOC article mentioned in Post 369990 (otto: "concerning: aziridines", Novel Discourse) is as follows:


Desulfonylation of chiral N-sulfonyl aziridines
Alonso DA. Anderson PG.
J. Org. Chem. 63, 9455 (1988)
DOI:10.1021/jo9815296



The reaction is performed with Mg/MeOH. With stirring the yield is ~55% and with ultrasound ~78%.