SFTP in R on a Mac

I am working on a project where I need to upload PDFs generated from Rmarkdown to a SFTP server. The sftp R package is a nice wrapper to the RCurl package for handling SFTP access. But to my surprise, SFTP support is not included on Macs by default through the curl command. After some research I found the curl-openssl formula that includes SFTP support. However, since curl is a build-in program for Mac OS brew install will not install it into the PATH environment, therefore not being directly available.