474090-40-9Relevant academic research and scientific papers
Highly regioselective construction of spirocycles via phosphine-catalyzed [3 + 2]-cycloaddition
Du, Yishu,Lu, Xiyan,Yu, Yihua
, p. 8901 - 8905 (2002)
A direct entry to spirocycles with low to moderate regioselectivity was achieved by triphenylphosphine-catalyzed [3 + 2]-cycloaddition of active exo-methylenecycles (1) and ethyl 2,3-butadienoate (2). The regioselectivity of the reaction was greatly impro
Synthesis of carbocyclic hydantocidins via regioselective and diastereoselective phosphine-catalyzed [3 + 2]-cycloadditions to 5-methylenehydantoins
Pham, Tien Q.,Pyne, Stephen G.,Skelton, Brian W.,White, Allan H.
, p. 6369 - 6377 (2007/10/03)
The phosphine-catalyzed [3 + 2]-cycloaddition of 5-methylenehydantoins 4 with the ylides 5, derived from addition of tributylphosphine to the 2-butynoic acid derivatives, 6a-d, gives spiro-heterocyclic products. The camphor sultam derivative 6b gives optically active products. Noteable was that the ylides derived from ethyl 2-butynoate and the 3-(2-butynoyl)-1,3-oxazolidin-2-one derivatives 6c and 6d gave spiro-heterocyclic products with reverse regioselectivities. The N,N-dibenzylprotected cycloadduct has been converted to carbocyclic hydantocidin and 6,7-diepi-carbocyclic hydantocidin.
Regioselective and diastereoselective phosphine-catalysed [3+2] cycloadditions to 5-methylenehydantoins: Reversal of regioselectivity using chiral N-2-butynoyl-(4S)-benzyloxazolidinone
Pham, Tien Q,Pyne, Stephen G,Skelton, Brian W,White, Allan H
, p. 5953 - 5956 (2007/10/03)
The phosphine-catalysed [3+2] cycloaddition of 5-methylenehydantoins 1 with the ylides 2a and 2b gives spirocyclic products with reverse regioselectivities; the latter ylide gives optically active products.
