Studies On Free-radical Initiated C-C（P） Bond Formations Via Selective C_sp3-H（P-H） Functionalization

Four novel methods of construction of C-C(C-P) bonds via free-radical-initiated selective CH functionalization have been demonstrated in this thesis, which is divided into five sections as following.Chapter 1 reviews the advances in free-radical-promoted C-H functionalization(Csp3-H activation especially). It begins by presenting the developments of free-radical-promoted Csp3-H activation shortly. And the type of free-radical-initiated C-H(P-H) activation has been described in details:(1) Studies on synthesis of oxindoles through free-radical cascade reaction.(2) Research on preparation of heterocycles such as phenanthridine, quinoline, isoquinoline and so on via freeradical cascade process.(3) Investigations on the coupling reaction of organophosphorus compounds with simple alkenes or alkynes.(4) Strategies for preparation of alkyl nitriles.Chapter 2 summarizes a novel protocol to synthesize alkyl substituted oxindoles. We found that the reaction of various acrylamides with simple alkanes or toluenes can effectively give the corresponding oxindoles under the conditions: Cu2 O as catalyst, dicumyl peroxide as radical initiator, 110 oC.Chapter 3 demonstrates a free radical cascade cyclization of isocyanides with simple alkanes and alcohols to prepare various substituted phenanthridines. And the reaction can efficiently proceed under the typical conditions: CuF2 or Cu2 O as catalyst, dicumyl peroxide as radical initiator, 110 oC.Chapter 4 reports a silver initiated free-radical anti-Markovnikov addition reaction of unactivated alkenes with phosphonates. The ESR studies and radical clock experiments support the free-radical pathway.Chapter 5 develops a radical addition of nitriles with unactivated alkenes, which could be applied to preparing a wide range of substituted alkylnitriles under the reaction conditions: CuI as catalyst, dicumyl peroxide as radical initiator, N2, 110 oC. The reaction could proceed in very high selectivities, good yields and large scales.In summary, we provide some novel strategies for preparation of useful organic compounds such as oxindoles, phenanthridines, substituted phosphonates, alkylnitriles and so on, which could be applied widely in organic synthetic chemistry.