Rearrangement allyl cyanate-isocyanate

An account has appeared166 of [3,3]-(and [2,3]-)sigmatropic rearrangements of propargyl precursors that lead to the synthesis of allenes bearing functional groups with at least two heteroatoms (see Scheme 36). The allyl cyanate to isocyanate rearrangement has been established as a new synthetic method for the construction... 

Y. Ichikawa, M. Osada, I. I. Ohtani, and M. Isobe, A new synthetic method for the preparation of amino sugars through an allyl cyanate-to-isocyanate rearrangement, J. Chem. Soc., Perkin Trans. 1, (1997) 1449-1455. 

Banert, K., Melzer, A. The first direct observation of an allylic [3,3] sigmatropic cyanate-isocyanate rearrangement. Tetrahedron Lett. 2001, 42,6133-6135. 

Allyl cyanates undergo a [3,3] sigmatropic rearrangement to allyl isocyanates, as depicted in reaction 36. ... 

Synthesis of nitrogen-containing natural products using allyl cyanate-to-isocyanate rearrangement 06Y96. 

A synthesis of the marine diterpene geranyllinaloisocyanide 1652 has been successfully accomplished by a novel regioselective allylamine construction, which is achieved by an allyl cyanate-to-isocyanate rearrangement 1649 —> 1650. The resulting formamide 1651 is dehydrated with triphenylphosphane/tetrabromomethane to give the geranyllinaloisocyanide 1652 in 82% yield [1226]. 

A [3,3]-sigmatropic cyanate-isocyanate rearrangement has been identified as a route to a-isocyanato allylboronic esters that can be trapped with nucleophiles (Scheme 2). A DFT (density functional theory) investigation of [3,3]-sigmatropic rearrangement versus a [2 4-2]-cycloaddition of a formal 5 2 substitution of imido metal complexes with allylic electrophiles has been reported (Scheme 3). ... 

Ichikawa and co-workers have published a number of papers disclosing an allyl cyanate to isocyanate rearrangement and its application to the synthesis of aminosugars [44,45]. A nitrogen substituent can be introduced into the pyra-... 

The 5-(2-alkenyloxy)thiatriazoles on thermal degradation gave alkenyl isocyanates by a presumed allylic rearrangement of the expected 2-alkenyl cyanates.54 Although the data do not exclude decomposition via intramolecular cyclic attack at the 4-position in the ring followed by very rapid decomposition of the 4-substituted thiatriazolines, these... 

From Unsaturated Sugars. — Allylic rearrangement of ally cyanates, formed in situ from carbamates such as 24 (derived originally from o-glucal triacetate), yielded isocyanates, e.g. 25, that could then be converted to allylic amine derivatives, e.g. 26 (Scheme 6). Trapping of an allylic... 

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