Asymmetric double hydroboration of 1,3-dienes catalyzed by chiral phosphine-rhodium complexes

✍ Scribed by Yonetatsu Matsumoto; Tamio Hayashi

• Publisher: Elsevier Science
• Year: 1991
• Tongue: French
• Weight: 310 KB
• Volume: 32
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)92714-x

✦ Synopsis

Suntnuzry: Reaction of I-phenyl-1,3-butadiene with catecholborane in the presence of a rhodium catalyst bearing ~a~lphosphine ligand such as PPh3 or dppf proceeded regioselectively to give, after oxidation, anti-l-phenyl-1,3-butanediol in a good yield. Use of (R)-BINAP as a chiral ligand for the catalytic hydroboration gave optically active (lS,3R)-1-phenyl-1,3-butanediol of up to 67% ee.

Recent reports on rh~um-cat~yz~ hy~o~mtion of olefins have demonstrated its great potential in organic synthesis.1 We have previously reported that asymmetric hydroboration of substituted styrenes with catecholborane in the presence of a cationic rhodium-phosphine catalyst proceeded mgiospecifically to give, after oxidation, optically active 1-aryletbanols of over 90% ee. 2 Here we report a new type of catalytic asymmetric hydroboration where the addition of two molecules of catecholborane to 1-phenyl-1,3-butadiene takes place with high regio-and stereoselectivity.

Reaction pathway of catalytic hydroboration of 1-phenyl-1,3-butadiene (1) with catecholborane was found