How about the MSR Hubba Hubba (or even HP version) for 1.9kg? Reviews are excellent for this ultralight tent.
Vaude Hogan Ultralight 1 tent is 1.49kg.
Vaude Taurus Ultralight is 1.9kg.
Vango Ultralite 200 is 1.38kg and very affordable.
There are quite a few big brands doing ultralights now...depends on budget, how many skins you want, porch space, etc etc...check out MSR and Vaude, as these are often a good starting point.
Any other needs to narrow it down?