Kazuyuki Sasakura

Aminohaloborane in Organic Synthesis. IV.1 A Directed Aldol Condensation Using Vinylaminodichloroborane

Abstract Continuing our studies on the specific ortho substitution reaction of anilines,2 we tried to extend this methodology to directed aldol condensation3. Namely, N-cyclohexylidencyclohexylamine 1 was treated with boron trichloride and triethylamine in dichloromethane giving N-cyclohexyl-N-1-cyclohexenylaminodi-chloroborane 2, to our knowledge, a new type of aminohaloborane. Similar treatment of N-2-butyliden-cyclohexylamine 3 gave N-cyclohexyl-N-2-butenylamino-dichloroborane (a mixture of E and Z isomers) 4. The physical data satisfied the assigned structures.

Simple Synthesis of 1-(Azacycloalkyl)Indoles Using Exclusive Ortho α-Chloroacetylation of N-(Azacycloalkyl)Anilines

Abstract Use of 2-(azacycloalkyl)amino-α-chloroacetophenones (4) as starting material makes possible simple synthesis of 1-(azacycloalkyl)-indoles (2).

Aminohaloborane in organic synthesis. VIII. A one-step synthesis of 2-Aminobenzhydrols from anilines

Abstract 2-Aminobenzhydrols were obtained regiospecifically from anilines and benzaldehydes with the aid of phenyldichloroborane and triethylamine via N-anilinophenylchloroborane.

Aminohaloborane in Organic Synthesis. VII.1A Directed Aldol Condensation Using Vinyloxyaminochloroborane

Abstract Vinyloxydichloroboranes (1) are scarcely found in literature2 probably because of certain unstable properties. We have found that some vinyloxyamino-chloroboranes (2), which can be prepared by formal substitution of one chlorine atom of 1 with a diethylamino group, are isolable stable compounds.

Simple Synthesis of Pyrrolo[3,4-c]-Quinoline-3-Ones and Pyrrolo[3,4-c]Quinoline-3,4-Diones

Abstract The use of 2-amino-α-chloroacetophenones (1) as starting material makes possible a simple synthesis of new types of pyrroloquinolines (2, 5) and pyrroloquinolones (3).

Simple Synthesis of 3-Alkyl-1H-Indazoles Having Functional Groups At the ω-Position

Abstract 3-Alkyl-1H-indazoles (1) having a functional group at the ω-position can be simply synthesized by using 2-(ω-chloroalkanoyl)-anilines (3) as starting material.