Please see https://cbcrypt.org specifically https://cbcrypt.org/doku.php#documentation_and_api. There is a method
CBCrypt.GenerateKeyPair(string CBCryptHostId, string username, string password) created specifically for this purpose.
This does not relate specifically to BitCoin, but if you start with something like a password, salt it with details of where you're going to send it, stretch it with something like SCrypt, use the result to seed a PRNG from which an asymmetric key factory derives a key, then you have deterministically derived an asymmetric key from the password. CBCrypt does this with ECDH, but in theory you could do it with any key type you wished.
It is important for such a system to have a rate limiting function applied before deriving the resultant key, before sending the public key to another party. However, salting & stretching can only help so much.
If you have a password with only 11 bits of entropy in it (for example, your password is a common dictionary word) then an attacker can still crack your password in ... let's say 250 seconds guaranteed (4 minutes) or 125 sec expected (2 minutes, >50% probability) with a mediocre laptop.
Even with good salting & stretching applied with a good rate limiting function such as SCrypt, let's assume an attacker is able to guess 4 guesses per second per CPU core they have available. A moderate attacker 400 guesses per second, call it 4,000 guesses per second. Assume they have more efficient algorithms than you - because they benchmarked the hell out of everything available, and maybe have hardware acceleration. They can do 40,000 guesses per second. If you want your password to withstand 10 years of brute force with 99% certainty, you'll need log2((40000*60*60*24*365*10)/0.01) ~= 51 bits of entropy in your password. Remember, this is a moderate attacker, with a moderate level of certainty. A sophisticated attacker could be much larger, and if the value of what you're protecting is higher, then you'll also need a much higher level of certainty than 99% in 10 years.