Transition Metal Catalyzed Transformation Of Enamines And Synthesis Of Chiral Allene

Synthesis of nitrogen-containing molecules has been a hotspot in organic chemistry for its distribution in many lives and drug molecules. Enamine, as an important synthesis precursor of complex nitrogen compounds, not only react as an ordinary olefins, but have the specific reactivity. Enamine are applied to a variety of synthesis and conversions.As a simple and efficient method, Heck reaction has been widely used in organic synthesis. In particular, there has been a great interest in the use of transient palladium complex generated from a Heck reaction for domino reactions to construct complex polycycles for its building multiple bonds at same time. This transient palladium complex may be involved in β-elimination, sp3or sp2C-H bond activation, Pd migration, etc to yield complex structures. It is the difficulty to develop this method due to harsh reaction conditions.In light of our interest in the use of transient palladium intermediate for domino reaction, we studied the palladium-catalyzed reaction using N-(2-bromobenzyl)-N-(1-phenylvinyl)acetamide. We have successfully developed a new and efficient strategy using one simple starting material for selective synthesis of four types of products by tuning the used ligands and bases in the reactions:1. Highly selective6-endo Heck cyclization reaction for the synthesis of dihydroisoquinoline derivatives.2. The1,1’-disubstituted ethylene derivatives could be synthesized under basic condition via intramolecular Heck coupling reaction followed by a β-N-Pd elimination processes.3. It reported the synthesis of5/5-membered fused ring systems by employing a sequence of5-exo-trig Heck coupling,1,4-palladium alkyl to aryl migration and intramolecular oxidative diaryl cross-coupling steps in one pot.4. We also achieve C(sp3)-C(sp3) formation through σ-alkylpalladium induced C(sp3)-H domino activation to synthesis of pyrroloisoindolone derivatives.Allenylsilanes are important segments of biologically active molecules and useful organometallic reagents in organic synthesis for their applicability toward various transformations such as nucleophilic substitution and cyclization reactionSynthesis of Allenylsilanes by simple silicon couplet is less, especially more rare of chiral allenylsilanes We developed a new method for synthesis multisubstitude allenylsilanes via1,6addition of silicon-boron reagents and unsaturated conjugate enyens.Under Mild reaction condition, a variety of aromatic and aliphatic substituted allenylsilanes was prepared in high yield. In addition, we also syntheze chrial allenylsilanes controled by chiral ligands though this1,6addition. Various aromatic ring substituded allenylsilanes were developed with excellent enantioselectivity. Allenylsilanes were well transformed by reduction or cyclization induced by elecrrophilic reagents...