Highly Regioselective Nucleophilic Addition Of 3-Cvclopropylideneprop-2-en-1-ones And Its Applications

Allenes,a subclass of organic molecular with high and unique reactivities,have emerged as an important and useful building block in contemporary synthesis,and a variety of valuable transformations have been realized.Nucleophilic addition of allenes constitutes highly synthetically versatile processes because they could provide an efficient way to form a new C-C or C-heteroatom bond with enormous potential.However,an attractive but often troublesome feature of allenes is their multiform reactivities that may lead to formation of different products.Allenes with functional groups attached to the end of C=C bonds will significantly change their electronic cloud distribution,for example,the presence of electron-withdrawn groups may facilitate the selective nucleophilic attack at the central carbon of allenes,thus delicately controlling the regio-and stereoselectivity of the reactions.3-Cyclopropylideneprop-2-en-1-ones,an analog of allenes with highly strained cyclopropyl ring and carbonyl group adjacent to the two ends of cumulated double bonds,have reprecented versatile reactivities.Complex organic molecules could be constructed by the reaction of 3-cyclopropylideneprop-2-en-1-ones and different nucleophilic reagents with high regio-and stereoselectivities.Herein,we have developed the following reactions:Firstly,we have disclosed a solvent-dependent hydrosulfonylation of 3-cyclopropylideneprop-2-en-1-ones with sodium sulfinates.The corresponding ?-or ?-addition products can be produced in good to excellent yields with high selectivities,respectively.A rationale for these transformations is proposed base on the controlled experiments.Meanwhile,a highly efficient 5-endo-trig cyclization reaction of ?-adducts in the presence of iodine to afford the tetrasubstituted furans is described.Finally,the results of the postcyclization modifications are also presented.Secondly,the highly solvent-controlled reactions of 3-cyclopropylideneprop-2-en-1-ones with sodium nitrite have been introduced.The ?,?-dinitration products,?-nitration products,and oximes were obtained with highly chemoselectivities by employing MeCN,DMSO,and MeOH as solvents.