Development of an efficient method for synthesizing N-heterocyclic compounds based on a divalent titanium complex

一种新的钛复合体（β I-D12-D1-丙烯）Ti（O-i-Pr）Ti D24-D2，与2 equiv的i-PrMgX （X = Cl或Br），作为一种通用钛（II）相等以影响后续独特的转变。因此， alkynes反应1对alkyne-titanium类型的复合体（β y D12 y D1-alkyne）Ti（O-i-Pr）alkynes D22 y D2，可以作为一种有机乙烯基dianion等价物在各种电磁药的反应中使用。酰亚胺和芦荟钛可以准备好从酰亚胺或丙酰亚胺衍生物通过1个氧化物添加途径的反应。当乙酰酯类在内核化学乙酰基取代（INAS）中得到的反应对afford α、β-不饱和碳基化合物、olefinic酯类Unergo Tandem INAS和内核碳基添加反应对给予环丙烷的反应。Ene-ene、ene-yne和yne-yne偶联反应发生在一个内部或内分子方式中，以及通过一个化学-、regio-、立体声方式中的不同电泳反应中，通过合成N-异环和/或他们的前体，其中包括五聚氰胺、幽门螺杆菌、印度元、光学活性N-异环、2，6-干扰性吡啶、β-乳糖、氮杂素和γ-氨基碳基化合物。

A new titanium complex (ηィイD12ィエD1-propene)Ti(O-i-Pr)ィイD22ィエD2 (1), generated in situ by treatment of Ti(O-i-Pr)ィイD24ィエD2 with 2 equiv of i-PrMgX (X = Cl or Br), nicely acts as a versatile titanium(II) equivalent to effect the following unique transformations. Thus, alkynes react with 1 to afford the alkyne-titanium complexes of type (ηィイD12ィエD1-alkyne)Ti(O-i-Pr)ィイD22ィエD2, which could be utilized as a vicinal vinylic dianion equivalent in the reactions with various kinds of electrophiles. Allyl- and allenyltitaniums could readily be prepared from allylic or propargylic alcohol derivatives by the reaction with 1 through an oxidative addition pathway. While acetylenic esters resulted in an intramolecular nucleophilic acyl substitution (INAS) reaction to afford α,β-unsaturated carbonyl compounds, olefinic esters undergo tandem INAS and intramolecular carbonyl addition reactions to give cyclopropanols. Ene-ene, ene-yne, and yne-yne coupling reactions proceed in an intra- or intermolecular way via a cyclometallation reaction, and the generated titanacyclic complexes react with a variety of electrophiles in a chemo-, regio-, stereoselective way.By utilizing these reactions, we have now succeeded in synthesizing N-heterocycles and/or their precursors, which include quinolones, pyrroles, indoles, optically active N-heterocycles, 2,6-disubstituted piperodines, β-lactams, azasugars and γ-amino carbonyl compounds.