can I use iphone to Mac airdrop on a Mid 2010 IMac?

I followed the directions in the link you included above and it says that air drop is supported.

As others have pointed out, you must have missed the part about iPhone / iPad, etc support, or not read the document carefully.

To send items to an iPhone, iPad, or iPod touch, orto receiveitems from those devices, you need a 2012 or later Macmodel with OS X Yosemite or later, excluding the Mac Pro (Mid 2012).

You told us that you have a 2010 iMac.

Unfortunately, you will need a 2012 or later iMac to use AirDrop. More info here:

http://www.idownloadblog.com/2015/06/23/how-to-mac-compatible-airdrop/

As I stated previously you can not use airdrop from a 2010 imac to an iOS device

*To send items to an iPhone, iPad, or iPod touch, or to receive items from those devices, you need a 2012 or later Mac model with OS X Yosemite or later, excluding the Mac Pro (Mid 2012).

To send items to another Mac, you need:

• MacBook Pro (Late 2008) or later, excluding the MacBook Pro (17-inch, Late 2008)
• MacBook Air (Late 2010) or later
• MacBook (Late 2008) or later, excluding the white MacBook (Late 2008)
• iMac (Early 2009) or later
• Mac Mini (Mid 2010) or later
• Mac Pro (Early 2009 with AirPort Extreme card, or Mid 2010)

* Source

Use AirDrop to send content from your Mac - Apple Support

Bob is correct.

You can send on a 2010 iMac to another Mac running AirDrop in OS X but not to another iOS device.

The following should be the minimum requirements to use AirDrop to move files between your iPhone 6 Plus and your 2010 iMac:

• OS X Lion+ on the receiving device.
• iOS 7+ on the sending device.
• iMac Early 2009+
• Bluetooth 4.0 & Wi-Fi enabled.
• iCloud is not required unless you only want to AirDrop with your Contacts, in which both parties must be signed into the same iCloud account.

Ref:

• How to tell if your Mac supports AirDrop - iDB
• Pro tip: Troubleshooting AirDrop on iOS - TechRepublic
• AirDrop not working? Here's the fix! - iMore
• AirDrop not working? Try these troubleshooting tips - iDB
• AirDrop Not Working? Troubleshoot Your File Transfer Woes - MUO

Ah yes. A simple cut and paste error in my notes which I didn't double-check before replying to the OP. Thanks for the correction.

Please see the specs quoted below.

To send items to an iPhone, iPad, or iPod touch, or to receive items from those devices, you need a 2012 or later Mac model with OS X Yosemite or later, excluding the Mac Pro (Mid 2012).

From: Use AirDrop to send content from your Mac - Apple Support