For the next 48 years Boas led the Adelaide Hebrew Congregation. One of his first tasks was to consecrate the new synagogue in Rundle Street, Adelaide. Boas also travelled as far afield as Perth and Coolgardie, Western Australia, to open new schools and synagogues.

Boas was a scholar in literature, particularly Shakespeare on whom he gave talks. He was vice-president of the (Adelaide) University Shakespeare Society from 1888. Boas was chairman of the board of trustees of Estcourt House (a home for the aged and crippled), member of the council of the District Trained Nurses' Association, a foundation member of the District Trained Nursing Society and involved with a number of other philanthropic and cultural organisations.