A novel synthetic strategy employing benzyne and azomethine ylides for the construction of spiro[oxindole-3,2′-pyrrolidine] derivatives has been achieved in good yields. The ketimines obtained from the condensation of isatins with CF 3 CH 2 NH 2 react with benzyne in the presence of weak bases such as TBAF or TBAT. This mild practical 1,3-dipolar cycloaddition provides an efficient route to access biologically active compounds. Note pubs.acs.org/joc

An unprecedented three-component reaction of arynes, tertiary amines, and nucleophiles has been demonstrated through ammonium salt intermediates. This protocol allows access to tertiary aniline derivatives containing the piperazine motif in good-to-excellent yields. Expansively, this reaction can produce biologically important 2-(4-phenylpiperazin-1-yl)ethyl-containing molecules using arynes, 1,4-diazabicyclo(2.2.2)octane (DABCO), and nucleophiles via a one-pot process.

A chemo-and site-selective reduction reaction of isatin derivatives using catalyst B(C 6 F 5 ) 3 and hydrosilanes is described. This transformation is operationally simple, proceeds under mild conditions, and is resistant to various functional groups. Thus, this efficient reaction using a combination of B(C 6 F 5 ) 3 and BnMe 2 SiH or B(C 6 F 5 ) 3 and Et 2 SiH 2 could potentially be utilized to produce various indolin-3-ones and indolines, without the need for multistep procedures and metal catalysis conditions. Letter pubs.acs.org/OrgLett

An efficient chemoselective reduction of isatin derivatives using catalyst B(C 6 F 5 ) 3 , benzyldimethylsilane, and H 2 O is described. Notably, a small amount of water is shown to be a highly effective reaction promoter that decreases the reaction time and temperature for the synthesis of indolin-3-ones. Moreover, using method, excellent deuterium incorporation is achieved via the catalytic α-deuteration of indolin-3-ones using B(C 6 F 5 ) 3 and D 2 O.

An unprecedented synthetic approach involving umpolung allylation/aza-Prins cyclization of N-2,2,2-trifluoroethylisatin ketimines is described. The reactions proceed smoothly with allyl bromide in the presence of 1,8-diazabicyclo[5.4.0]­undec-7-ene, H2O, and trimethylsilyl bromide; this one-pot protocol allows access to six-membered spiro azacyclic oxindole derivatives in good to excellent yields. Notably, while the general aza-Prins cyclization involves amines and aldehydes, the present synthetic strategy represents the first aza-Prins cyclization that utilizes the umpolung property of N-2,2,2-trifluoroethylisatin ketimines.