TY  - JOUR
A1  - Liu, Xiaocui
A1  - Ming, Wenbo
A1  - Friedrich, Alexandra
A1  - Kerner, Florian
A1  - Marder, Todd B.
T1  - Copper-Catalyzed Triboration of Terminal Alkynes Using B\(_2\)pin\(_2\): Efficient Synthesis of 1,1,2-Triborylalkenes
JF  - Angewandte Chemie International Edition
N2  - We report herein the catalytic triboration of terminal alkynes with B\(_2\)pin\(_2\) (bis(pinacolato)diboron) using readily available Cu(OAc)\(_2\) and P\(^n\)Bu\(_3\). Various 1,1,2‐triborylalkenes, a class of compounds that have been demonstrated to be potential matrix metalloproteinase (MMP‐2) inhibitors, were obtained directly in moderate to good yields. The process features mild reaction conditions, a broad substrate scope, and good functional group tolerance. This copper‐catalyzed reaction can be conducted on a gram scale to produce the corresponding 1,1,2‐triborylalkenes in modest yields. The utility of these products was demonstrated by further transformations of the C−B bonds to prepare gem ‐dihaloborylalkenes (F, Cl, Br), monohaloborylalkenes (Cl, Br), and trans ‐diaryldiborylalkenes, which serve as important synthons and have previously been challenging to prepare.
KW  - boronate esters
KW  - borylation
KW  - cross-coupling
KW  - diboration
KW  - halogenation
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-206694
VL  - 59
IS  - 1
ER  - 
TY  - JOUR
A1  - Liu, Xiaocui
A1  - Ming, Wenbo
A1  - Luo, Xiaoling
A1  - Friedrich, Alexandra
A1  - Maier, Jan
A1  - Radius, Udo
A1  - Santos, Webster L.
A1  - Marder, Todd B.
T1  - Regio‐ and Stereoselective Synthesis of 1,1‐Diborylalkenes via Brønsted Base‐Catalyzed Mixed Diboration of Alkynyl Esters and Amides with BpinBdan
JF  - European Journal of Organic Chemistry
N2  - The NaOtBu‐catalyzed mixed 1,1‐diboration of terminal alkynes using the unsymmetrical diboron reagent BpinBdan (pin = pinacolato; dan = 1,8‐diaminonaphthalene) proceeds in a regio‐ and stereoselective fashion affording moderate to high yields of 1,1‐diborylalkenes bearing orthogonal boron protecting groups. It is applicable to gram‐scale synthesis without loss of yield or selectivity. The mixed 1,1‐diborylalkene products can be utilized in Suzuki–Miyaura cross‐coupling reactions which take place selectivly at the C–B site. DFT calculations suggest the NaOtBu‐catalyzed mixed 1,1‐diboration of alkynes occurs through deprotonation of the terminal alkyne, stepwise addition of BpinBdan to the terminal carbon followed by protonation with tBuOH. Experimentally observed selective formation of (Z)‐diborylalkenes is supported by our theoretical studies.
KW  - boronate esters
KW  - borylation
KW  - cross‐coupling
KW  - synthesis design
KW  - structure elucidation
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214728
VL  - 2020
IS  - 13
SP  - 1941
EP  - 1946
ER  -