In the past few years I have built several pieces of furniture with single corner dovetails. When I say single corner joints I mean multiple dovetails fixing two or three pieces of wood together "A single corner" . There is always sides unsupported, Never a full shape like a square .
I haven't seen a lot of examples of single corner furniture. Maybe because 4 corner dovetail construction, has been around for so long and has stood the test of time. The like of chests and drawers constructed with dovetails are common , and it is also common to see these examples with some age to them, with some examples from the 1700s still standing . This is because the dovetail joint is a strong joint and has been around since 3000bc , and has been seen in early Egyptian furniture.
So if the above examples can last for all that time , it gives good indication that, single corner dovetail construction is viable if used with careful thought.
Some time ago I built my second chair which , uses dovetails to connect the seat and backrest. While the chair doesn't look great, and the dovetails aren't neat, they are rock solid , still after 2.5 years of daily use, with no sign of movement.
You can imagine the stress, that is imposed upon the backrest of a chair. Daily use with people leaning back on it, the chair being drag and picked up by its backrest. Yet , still the dovetails are as strong as the day the glue dried on the joints.
Another good example of this type of construction is a side/serving table. Again this is not a full square created but , a 'U' shape. The table was made so I could eat my meals off it, while sitting on the sofa. This was due to a lack of space for a dining table. At the time I was in a rush (as always), so building it the way I did , was quick. And I was sure the dovetails would be fine. Surely enough I was right. Same again, there was daily use with the table. It was sat on, stood on as a step up, used as a foot rest, a coffee table and a serving table.
It's a very useful table, with many uses. The table received lots of abuse , and still the dovetails haven't budged .
Also very recently, I built a sofa containing dovetails. Although there is a full square , there is a large portion unsupported . The unsupported section supports like a back rest. And recently supported 2 person's without any problems.
Although the sofa is new, I've no doubt it will last for years.
I have also just built a coffee table , which is a bigger version of the serving tables. To look at it , you'd think it would break easily but, you can stand on it and sway back and forth (yes, I did do this) and it doesn't budge. Yet another example of the strength of dovetails.
So can you build furniture with single corner dovetails? Most definitely. Is it the best option? No, definitely 4 corner construction is stronger. However with the experience I've had , it is viable to use this construction. Obviously, there are limitations but, I'll have no hesitation to use this construction in the future.
If you are going to construct something with 2 or 3 sides, I would recommend the following
The dovetails should be multiple . For example instead of 1 or 2 in a 100mm board ,try to fit 4 or 5 . Adding extra will add considerable strength.
Use 80° dovetails. These are easier to cut and considered more for general purpose. And in my opinion stronger then stepper angles.
Have tight fitting joints. In my opinion dovetails should have to be tapped home lightly with a mallet/hammer or your fist.
Use PVA glue. In my experience PVA is stronger . I've never had much luck with cold hide glue. And I can't comment on hot hide glue. But, I've never been let down with PVA glue, I can't say the same for cold hide glue.
Have some faith in your dovetails and you'll not go far wrong. Happy dovetailing!
You can also watch me build the coffee table in a YouTube video, which has a lot of detail, on how I make my dovetails, with minimal tools and a simple low bench.