Indium(III) Chloride-Promoted Intramolecular Addition of Allylstannanes to Alkynes

Abstract

In the presence of an equimolar amount of InCl(3), 8-tributylstannyl-6-octen-1-ynes (allylstannanes bearing an alkynyl group) were efficiently cyclized to 2-allyl-1-methylenecyclopentanes. In contrast, catalytic use of InCl(3) gave 2-allyl-1-(tributylstannylmethylene)cyclopentanes mainly by intramolecular allylstannylation. These cyclizations could proceed via intramolecular addition of an allylindium intermediate.

Regio‐ and Stereoselective Generation of Alkenylindium Compounds from Indium Tribromide, Alkynes, and Ketene Silyl Acetals

“…This reaction proceeds in an anti fashion as opposed to the general syn addition of carboindation using organoindium substrates. [3,4] We determined the X-ray structure of alkenylindium adducts, which furnishes experimental evidence for our proposed mechanism. To the best of our knowledge, this is the first crystallographic characterization of alkenylindium species as a carboindation product.…”

Intramolecular Carbostannylation of Alkynes Catalyzed by Silver(I) Species

“…9:1 E / Z selectivity), in the radical cyclization of substrates 1 performed in the presence of azobisisobutyronitrile (5 mol %) and Bu 3 SnH (10 mol %) 5. Conversely, when the reaction of 1 was promoted by GaCl 3 (1 equiv), products 2 were obtained exclusively, whereas a similar reaction with InCl 3 (1 equiv) led to 2 as the major products along with mixtures of 3 and 4 in very low yields 6–8…”

Regio- and Stereoselective Allylindation of Alkynes Using InBr3 and Allylic Silanes: Synthesis, Characterization, and Application of 1,4-Dienylindiums toward Skipped Dienes

“…Carbometalation is an important synthetic method in organic synthesis because organometallic compounds are produced with an expansion of the carbon framework [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. In particular, the allylmetalation of alkynes provides metalated skipped dienes (1,4-diene), which are effectively transformed to functionalized skipped dienes via sequential reactions [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Skipped diene units are present in many biologically important natural products, and are also versatile synthetic building blocks in organic synthesis [ 19 , 20 , 21 , 22 ].…”