Synthesis of Stereodefined Borylated Dendralenes through Copper‐Catalyzed Allylboration of Alkynes

• Published in: Angewandte Chemie International Edition Vol. 57; no. 31; pp. 9945 - 9949
• Main Authors: Rivera‐Chao, Eva, Fañanás‐Mastral, Martín
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 26.07.2018; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Alkynes; allylation; Boron; Chemical synthesis; Chemistry; Chemistry, Multidisciplinary; Copper; dendralenes; Dienes; multicomponent reactions; Physical Sciences; Regioselectivity; Science & Technology; Substitutes; multicomponent reactions; PRACTICAL SYNTHESIS; ALLYLIC CARBONATES; dendralenes; EFFICIENT ROUTE; ESSENTIAL OIL; BORONIC ESTERS; C-H ACTIVATION; CROSS-CONJUGATED TRIENES; COUPLING REACTION; copper; STEREOSELECTIVE-SYNTHESIS; allylation; boron; SUBSTITUTED STEREOGENIC CARBON
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201806334

An efficient method to access diversely substituted borylated dendralenes from simple and readily available materials is reported. This method is based on a multicomponent copper‐catalyzed allylboration of alkynes with diboron and a 1,4‐dibromo‐2‐butene which provides bromo‐ and boron‐substituted skipped dienes with a remarkable chemo‐, stereo‐, and regioselectivity. These products can be easily transformed into dendralenic organoboronates, which display an extremely versatile reactivity as demonstrated by novel selective transformations. With a skip in its step: The synthesis of borylated dendralenes is reported for the first time. The method is based on a copper‐catalyzed allylboration of alkynes with 1,4‐dibromo‐2‐butenes and diboron, and it provides multifunctional skipped dienes with remarkable chemo‐, stereo‐, and regioselectivity. These compounds are easily converted into synthetically versatile dendralenic organoboronates.