The intramolecular click reaction using 'carbocontiguous' precursors

作者：Patil Pravin C; Luzzio Frederick A^*

来源：Tetrahedron, 2017, 73(29): 4206-4213.

DOI：10.1016/j.tet.2016.11.016

• Click chemistry
• Cyclic carbohydrates
• Cyclic peptides
• Dipolar cycloaddition
• 1,2,3-Triazole

The synthesis and utilization of all carbon-chain 'carbocontiguous' azidoalkynyl precursors for an intramolecular click reaction is described. The substrates contain both azidoalkyl and ethynylmethyl groups which are conjoined by a 2-(phenylsulfonylmethyl)-4,5-diphenyloxazole lynchpin and are suitably disposed for ring closure. On promotion by copper salts, a number of cyclic click products having the 1,4-disubstituted endo-fused triazole component and the 4,5-diphenyloxazole component are obtained. In one case, removal of the phenylsulfonylmethyl group from the substrate prior to cyclization gave the 1,5-disubstituted exo-fused triazole. The utilization of CuSO4/sodium ascorbate system appears to be the optimal conditions for closure/cyclization and afforded the cyclized products in yields of 84-95%.

• 出版日期2017-7-20