Generation of Ben3yres Using TMP-Zincate

本文以R_2Zn（TMP）Li为催化剂，通过去质子化锌化反应制备了功能化的苯炔类化合物，并研究了配体对苯炔类化合物形成的影响。用Me_2Zn（TMP）Li对间位取代溴苯进行脱质子锌化反应，一锅法合成了各种3位取代的苯炔，特别是酯、酰胺、氰基等亲电取代基的3位取代的苯炔。另一方面，用^tBu_2Zn（TMP）Li/进行锌化，然后用I_2亲电捕获，证明是制备1，2，3-三取代芳香族化合物的有力工具。所得1，2，3-三取代苯可作为Me_3ZnLi与卤素-锌交换反应生成3-取代苯炔的前体。这些方法提供了比以前的方法更大的通用性功能化的不对称苯炔的合成，并应在各种天然产物和功能材料的新的合成的价值。此外，这些结果强调了ate配合物中心金属上的旁观者配体作为开发新的ate配合物促进反应中的可调功能的实用性。

We have developed new methods for preparing functionalized benzynes through deprotonative zincation as a key reaction using R_2Zn(TMP)Li, and we also describes dramatic ligand effects on the benzyne formation. Deprotonative zincation of various m-substituted bromobenzenes using Me_2Zn(TMP)Li proved effective for the one-pot generation of various 3-functionalized benzynes, particulary those with electrophilic substituents such as ester, amide, and cyano. On the other hand, zincation with ^tBu_2Zn(TMP)Li/ followed by electrophilic trapping (with I_2) proved a powerful tool for the preparation of 1,2,3-trisubstituted aromatic compounds. The resultant 1,2,3-trisubstituted benzenes are available as precursors for generation of 3-substituted benzynes by halogen-zinc exchange reactions using Me_3ZnLi. These methods offer far greater generality than previous methods for the synthesis of functionalized asymmetric benzynes, and should be value in new syntheses of various natural products and functional materials. In addition, these results underline the utility of spectator ligands on the central metal of ate complexes as a tunable functionality in the development of new ate complex-promoted reactions.