Judaism places great emphasis on just and moral business ethics. There are many commands that instruct fair business dealings and prohibit any impropriety. We are taught that the verse to “not place a stumbling block in front of the blind (Lev. 19:14)” is a Torah command to not give bad advice. And that moral teaching certainly applies here if you feel the advice you are told to give would not be in the best interests of your clients.
Initially I think that you should approach your boss and tell him that you feel that other products that you are marketing might be more suitable for your clients. If your boss is not interested in your opinion and only wants you to market certain products that you truly feel are detrimental to your clients’ needs you may have to weigh up the only two real possibilities. The first is that you work for your boss and that you should do as he asks you. The other option is to let your boss know that you feel that it is not possible for you to recommend products that you feel are not correct for your clients and then let your boss decide what he is going to do with that information. Of course, it may mean his dismissing you from your job and it may also carry with it some very negative repercussions such as his not being prepared to write you a letter of reference for any future jobs.
May you be guided by your ultimate “Boss” from Above to make the correct decision for you, your clients and your earthly boss. I wish you much success and fulfilment in this matter and in all that you do.