title: Regulation of diastereoselectivity in the carbocyclization of allenyl (S)-N-tert-butylsulfinimines through a three-component assembly.
abstract: Allenyl sulfinimines can be stereoselectively cyclized with hexamethylditin under palladium catalysis conditions followed by a selection of additives for an activated transmetalation. Reactivity and diastereoselectivity for the cyclization strongly depend on the characteristics of additives. A highly diastereoselective synthesis of five-membered rings is achieved from the reaction of the corresponding allenyl (S)-N-tert-butylsulfinimies through the following sequence. After the distannylation of the allenyl group with hexamethylditin catalyzed by the Pd complex, stereochemical routes are additive dependent: addition of SnCl4 affords a cis ring exclusively, whereas a trans ring is formed predominantly by the introduction of B-bromocatecholborane. Extension of the methodology to the synthesis of six-membered cis rings is achieved by using B-bromocatecholborane. Stereochemical relationships of products were unambiguously deduced by X-ray crystallography.
authors.forename: Jihyun
authors.initials: J
authors.lastname: Kim
authors.forename: Hyuna
authors.initials: H
authors.lastname: Kim
authors.forename: Nana
authors.initials: N
authors.lastname: Kim
authors.forename: Chan-Mo
authors.initials: CM
authors.lastname: Yu