How to connect iPhone 15 pro max to imac 27 late 2013

A USB-C to USB-A cable or adapter will work – but it has to be a cable capable of carrying data.

Many of the cheapest cables out there are "charging cables" that carry data only at USB 2.0 speeds, or not at all. A cable that does not have the data pins hooked up might be something you would want to use if you were going to charge from a public port where you were afraid of "juice jacking", but it's the last thing you'd want when trying to synchronize your iPhone with your Mac or PC.

Here's an example of a cable that should work. If you do a search, and then carefully peruse the results, I'm sure many others will turn up.

Amazon – Amazon Basics USB-C to USB-A 3.1 Gen 2 Adapter Charger Cable, Fast Charger, 10Gbps High-Speed, USB-IF Certified, Compatible with iPhone 15, iPad, Tablets, Laptops, 0.9 m, Black

Although Amazon calls this a "charger cable", the key specifications are that

• It has a USB-A plug on one end, and a USB-C plug on the other.
• It's rated to carry data at 10 Gbps speeds (USB 3.1 Gen 2 speeds – as high as USB-A can go – and higher than the USB-A ports on a Late 2013 iMac can go).

USB-IF certification isn't a bad thing to have, either.

The one drawback of this cable (which will probably be shared by any cable with a USB-A connector) is that it only supports 15W charging – traditional USB 5V/3A power. USB Power Delivery is, as I understand it, a USB-C thing; and an iPhone connected by a USB-C to USB-C cable to a USB-C power adapter could presumably negotiate higher charging power (if both sides agreed upon it).

I apologize for my response above.

Perhaps something like this cable is what you are looking for.

Otterbox USB-C to USB-A Charging Cable

I tried with a usb-c to USB and its not recognized at all on my 2012 MacPro

The USB-3 connection ports should accept the USB-C cable.

I think you (we) need a USB C to USB 3 adapter. If you google that, you'll get a variety of sources that sell them. I tried attaching an Amazon link but that's not allowed.