原句等于：Whatever it is you are thinking about doing, it isn't going to happen.

Whatever it is you are thinking about doing 分析结果如下。

这是由whatever 引导的让步状语从句。该从句有两种分析方法：

1. 该从句包含一个定语从句 you are thinking about doing，先行词就是 whatever，并充当doing 的宾语。

2. 该从句使用了强调结构，强调了doing 的宾语 whatever。

还原为： You are thinking about doing whatever —— Whatever you are thinking about doing

强调结构：It is whatever (that) you are thinking about doing

变成让步从句：Whatever it is you are thinking about doing

我倾向第二种分析。因为按定语从句分析，it 指代唐突和不明。

原句实际是：

Whatever you are thinking about doing, it isn't going to happen.