Expanding Water/Base Tolerant Frustrated Lewis Pair Chemistry to Alkylamines Enables Broad Scope Reductive Aminations

Abstract Lower Lewis acidity boranes demonstrate greater tolerance to combinations of water/strong Brønsted bases than B(C 6 F 5 ) 3 , this enables Si−H bond activation by a frustrated Lewis pair (FLP) mechanism to proceed in the presence of H 2 O/alkylamines. Specifically, BPh 3 has improved water tolerance in the presence of alkylamines as the Brønsted acidic adduct H 2 O–BPh 3 does not undergo irreversible deprotonation with aliphatic amines in contrast to H 2 O–B(C 6 F 5 ) 3 . Therefore BPh 3 is a catalyst for the reductive amination of aldehydes and ketones with alkylamines using silanes as reductants. A range of amines inaccessible using B(C 6