Drawing your own mechanisms with curly arrow guide line

 Summary of Curly arrow:-

1. A curly arrow show the movement of a pair of electrons.

2. The tail of the arrow show the source of the election pair, which will be a filled orbital ( HOMO ) and can be represented by:

- a lone pair

- or a negative charge

- or a pie bond

- or a Sigma bond

3. The head of the arrow indicates the destination of the election pair, which will be:-

- an empty atomic orbitals where a new bond will be formed.

- or a Sigma antibonding or pie antibonding orbitals where a new bond will be formed and an old bond will break.

- or an electronegative atoms that can support a negative charge.

4. Overall change is always conserved in a reaction.

Note :- B, C , N, and O never have more than four bonds. If you make a new bond to uncharged H, C , N or O you must also break one of the existing bonds in the same step.