find -exec command options with basename

I have the following JPEG files :

$ ls -l
-rw-r--r-- 1 user group 384065 janv. 21 12:10 CamScanner 01-10-2022 14.54.jpg
-rw-r--r-- 1 user group 200892 janv. 10 14:55 CamScanner 01-10-2022 14.55.jpg
-rw-r--r-- 1 user group 283821 janv. 21 12:10 CamScanner 01-10-2022 14.56.jpg

I use $ img2pdf to transform each image into a PDF file. To do that :

$ find . -type f -name "*.jpg" -exec img2pdf "{}" --output $(basename {} .jpg).pdf \;

Result :

$ ls -l *.pdf
-rw-r--r-- 1 user group 385060 janv. 21 13:06 CamScanner 01-10-2022 14.54.jpg.pdf
-rw-r--r-- 1 user group 201887 janv. 21 13:06 CamScanner 01-10-2022 14.55.jpg.pdf
-rw-r--r-- 1 user group 284816 janv. 21 13:06 CamScanner 01-10-2022 14.56.jpg.pdf

How can I remove the .jpg part of the PDF filenames ? I.e., I want CamScanner 01-10-2022 14.54.pdf and not CamScanner 01-10-2022 14.54.jpg.pdf. Used alone, $ basename filename .extension prints the filename without the extension, e.g. :

$ basename CamScanner\ 01-10-2022\ 14.54.jpg .jpg
CamScanner 01-10-2022 14.54

But it seems that syntax doesn't work in my $ find command. Any idea why ? Note : if you replace $ img2pdf by $ echo it's the same, $ basename doesn't get rid of the .jpg part :

$ find . -type f -name "*.jpg" -exec echo $(basename {} .jpg).pdf \;
./CamScanner 01-10-2022 14.56.jpg.pdf
./CamScanner 01-10-2022 14.55.jpg.pdf
./CamScanner 01-10-2022 14.54.jpg.pdf