In　this　work,　six　novel　axially　unfixed　biaryl-based　water-compatible　bifunctional　organocatalysts　were　designed　and　synthesized　for　the　organocatalytic　access　to　a　variety　of　3-alkyl-3-hydroxy-2-oxindole　derivatives　via　aldol　reactions　in　water.　Organocatalyzed　by　5a,　the　direct　aldol　reactions　of　isatins　with　enolisable　ketones　underwent　readily　in　water,　furnishing　the　structurally　diverse　3-alkyl-3-hydroxy-2-oxindoles　in　various　stereoselectivities　(up　to　＞99%　dr　and　＞　99%　ee).　Moreover,　a　plausible　transition　state　of　the　conducted　aldol　reactions　was　hypothesized　to　shed　light　on　the　observed　stereoselectivities　of　the　obtained　3-alkyl-3-hydroxy-2-oxindoles.