Substituent effects on the regioselectivity of intramolecular carbene carbon-hydrogen insertion. Cyclizations of 1- and 5-substituted 2-adamantylidenes

Abstract

The syntheses of 1-3, KOPiv, and AgOPiv are described in our earlier paper. NaOPiv, LiOPiv and Et4NOPiv were prepared in the same way as was KOPiv. In the same paper are described the reactions of 1 with the pivalate salts and the NMR analysis of the products.

Face Selection in Addition and Elimination in Sterically Unbiased Systems

“…We see the adamantylidene carbene as a species in which C-2 has a filled sp 2 orbital and a vacant p orbital. A report bearing out this expectation has been published by Majerski . He studied the formation of dehydroadamantanes 24 and 25 in the Bamford−Stevens reaction shown below, and observed the product ratio to be 74:26 in favor of 24 when X is methyl, and 92:8 when it is chloro.…”

Iridium‐katalysierte Hydrochlorierung und Hydrobromierung von Alkinen durch Shuttlekatalyse

“…[4] Daher ist die Entwicklung von Verfahren zur Herstellung von Vinylchloriden von großer synthetischer Bedeutung. Der Zugang zu Vinylchloriden erfolgt im Allgemeinen über Carbonylverbindungen [5] oder Alkine. [6] Obwohl ein katalytisches Verfahren unter Verwendung von Carbonylverbindungen als Ausgangsmaterialien realisiert wurde, [5h] schränkt die Notwendigkeit von toxischen Phosphor-Reagenzien wie PCl 5 [5a,b] oder POCl 3 [5d] oder einem großen Überschuss an CrCl 2…”

Iridium‐Catalyzed Hydrochlorination and Hydrobromination of Alkynes by Shuttle Catalysis

“…[2] Moreover,vinyl chlorides have emerged as efficient coupling partners in crosscoupling reactions,s uch as the Suzuki-Miyaura coupling reaction [3] and the Buchwald-Hartwig amination. [4] Thus,the development of methods for the preparation of vinyl chlorides is of great synthetic significance.V inyl chlorides are generally accessed from either carbonyl compounds [5] or alkynes. [6] Although ac atalytic process using carbonyl compounds as starting materials has been realized, [5h] the requirement for toxic phosphorus reagents like PCl 5 [5a,b] or POCl 3 [5d] or al arge excess of CrCl 2 [5c] limits their applications in complex molecule synthesis.…”

“…Vinyl chlorides are generally accessed from either carbonyl compounds or alkynes . Although a catalytic process using carbonyl compounds as starting materials has been realized, the requirement for toxic phosphorus reagents like PCl 5 or POCl 3 or a large excess of CrCl 2 limits their applications in complex molecule synthesis.…”