Reactions of Sulfonyl Azides and Sulfonamides with Vinyl Ethers

Direct Asymmetric α‐Sulfamidation of α‐Branched Aldehydes: A Novel Approach to Enamine Catalysis

“…To the best of our knowledge there is no hard evidence for the existence of betaines resembling 47, but it seems to be widely accepted that a variety of fragmentation and decomposition reactions of triazolines derived from azides and electronrich olefins do in fact involve the formation of this type of intermediate. [87,88] The emergence of symmetrically substituted N,NЈ-disulfonyl-2,5-dimethoxypiperazines as side products in reactions between enol ethers and sulfonyl azides as a result of dimerisation seems to be a clear indication of the ring-opening of the cycloaddition product in an analogous manner. [87,89] On the other hand, ab initio calculations indicate that benzyl diazonium cations do not exist in the classical sense, but rather as electrostatically bound complexes between benzyl cation and dinitrogen.…”

Nucleophilic opening of the oxirane ring of 1-methyl-4-phenyl-3,4-epoxypiperidine

“…Again the participation of the nitrogen in a cyclic transition state apparently directed the course of the reaction and the greater steric bulk of the nucleophile caused elimination rather than addition at reaction temperatures near room temperature.6 Thus the product of the reactions of several lithium and magnesium reagents with 1 was 1 -methy 1-4-phenyl-1,2,3,6tetrahydro-3-pyridinol (9).7 The reaction of 1 with phenyl Grignard reagent in boiling anisóle occurred with some elimination to form 9, but two products of addition were also isolated (eq 2). These addition compounds were not identical with either of the diasterioisomers of 1-methyl-3,4-diphenyl-3-piperidinol formed by the addition of phenyl Grignard to l-methyl-4-phenyl-3-piperidone.2 One of the compounds was shown to be 1-methyl-4,4-diphenyl-3-piperidinol (10) on the basis of the elemental analyses, spectra, and comparison with reported melting point.8 Compound 10 was probably formed in a manner comparable with that of 2 from the hydride reductions, for 9 was inert to further reaction with phenyl Grignard reagent under these conditions.…”

Reactions of fluoroalkanesulfonyl azides with vinyl ether and tetrakis(dimethylamino)ethylene

“…In many case the similar intermediates A 0 gave the azilidine [5,6], imines [10][11][12], or oligmer [9] by elimination of N 2 or CH 2 N 2 (Scheme 3).…”

“…(1)). (1) In contrast, Franz et al [9] found that the vinyl ethers reacted with phenylsulfony azide gave the polymer as the major product accompanied other by-product which, however, are not fully characterized (Eq. (2)).…”