The regiospecific synthesis of 1H-indene-2-carbaldehyde derivatives was achieved through transition-metal-free, reductive cyclisation of ortho-formyl trans-cinnamaldehydes with Hantzsch ester in the presence of an aminocatalyst. In particular, cycloolefin isomerisation of the resulting products could be inhibited efficiently by the introduction of a sterically demanding stereo-defined aminocatalyst.

中文翻译：

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1 H-茚2-甲醛衍生物的有机催化区域特异性合成：通过使用空间要求苛刻的催化剂来抑制环烯烃异构化†

1 H-茚-2-甲醛衍生物的区域特异性合成是通过在氨基催化剂存在下用Hantzsch酯进行无过渡金属还原的邻甲酰基反式肉桂醛的环化反应而实现的。特别地，通过引入空间上需要的立体确定的氨基催化剂，可以有效地抑制所得产物的环烯烃异构化。