Practical Synthetic Reactions for Tine Chemical Using a Divalent Titanium Reagent

以Ti(O-i-Pr)_4和I-PrMgCl的两个等价物为原料合成的二价钛试剂，无毒、价廉，具有广泛的反应活性。因此，该试剂已被许多合成化学家广泛使用。进一步研究该试剂的反应开辟了新的有效的合成方法。1)合成1-α，25-二羟基-维生素D_3的实用合成方法，其中试剂介导的双不饱和化合物的环化是关键反应。2)由光学活性的烯丙基和丙叉基化合物分别合成手性和烯丙基钛试剂的方法及其合成用途。3)由内部和末端乙炔与试剂的金属Reppe反应的进展，4)合成1，4-二碘-1，3-烷二烯的实用方法及其在合成多取代共轭染料和π共轭低聚物中的应用。

A divalent titanium reagent developed by us which can be prepared from Ti (O-I-Pr)_4 and two equivalents of I-PrMgCl is non-toxic and inexpensive, and has versatile reactivity. The reagent therefore, has become widely used by many synthetic chemists.Further study of the reactions using the reagent opens up new efficient synthetic methods mentioned below.1) Practical synthetic method for preparing 1α, 25-dihydoxy-vitamin D_3 in which cyclization of bis-unsaturated compounds mediated by the reagent is a key reaction.2) Synthetic method of chiral allyl and alleyl titanium reagent from optically active allyl and propargyl compounds, respectively, and their synthetic utilization.3) Development of metalative Reppe reaction from internal and terminal acetylene and the reagent, which allows easy access to benzene and pyridine derivatives.4) Practical method to prepare 1,4-diiodo-1,3-alkadienes and their utilization for synthesizing polysubstituted conjugated dynes and π-conjugated linear oligomers.